Maharashtra Board Class 10 Science Chapter 3 Life Processes in Living Organisms Part 2 Solutions

 

Question 1. Complete the following chart.

Asexual reproduction	Sexual reproduction
1. Reproduction that occurs with the help of somatic cells is called asexual reproduction.	1. Reproduction that occurs due to fertilization of gametes is called sexual reproduction.
2. For asexual reproduction only one parent is necessary.	2. Male and female parents are necessary for sexual reproduction.
3. This reproduction occurs with the help of mitosis only.	3. This reproduction occurs with the help of both mitosis and meiosis.
4. New individual formed by this method is genetically identical with parents.	4. New individual formed by this method is genetically different from parents.
5. Asexual reproduction occurs in different individuals by various methods like binary fission, multiple fission, budding, fragmentation, regeneration, vegetative propagation, spore production, etc.	5. Sexual reproduction occurs in two steps: First formation of haploid gametes by meiosis and then fertilization of these haploid gametes to form diploid zygote. There are no subtypes in the sexual reproduction.

Answer: The completed chart is provided above.
In simple words: This chart clearly differentiates between asexual and sexual reproduction based on various parameters like parent involvement, cell division types, genetic similarity of offspring, and methods. It serves as a quick comparison guide for students to understand the fundamental differences between these two modes of reproduction.

🎯 Exam Tip: Questions involving comparative charts are common. Ensure you highlight key distinctions for each point, as demonstrated in the answer, to score full marks.

 

Question 2. Fill in the blanks.
a. In humans, sperm production occurs in the organ ............
(a) prostate gland
(b) testis
(c) ovaries
(d) Cowper's gland
Answer: (b) testis
In simple words: Sperm production, also known as spermatogenesis, takes place in the testes, which are the primary male reproductive organs.

🎯 Exam Tip: Knowledge of the specific organs responsible for gamete production in both male and female reproductive systems is crucial for questions like this.

 

b. In humans, ............ chromosome is responsible for maleness.
(a) X
(b) Y
(c) Z
(d) O
Answer: (b) Y
In simple words: In humans, the presence of the Y chromosome genetically determines maleness. If a Y chromosome is present, the individual develops as male.

🎯 Exam Tip: Remember the chromosomal basis of sex determination in humans (XX for female, XY for male) to accurately answer questions related to gender assignment.

 

c. In male and female reproductive system of human, ............ gland is same.
Answer: There is no similar gland in male and female reproductive system. There may be some homologies but there is no similarity.
In simple words: While some structures may be homologous, there isn't a single gland that is functionally identical and present in both the male and female human reproductive systems.

🎯 Exam Tip: Be precise in your understanding of anatomical structures; homologous structures may exist, but identical glands serving the same reproductive function in both sexes are not found.

 

d. Implantation of embryo occurs in ............
(a) ovaries
(b) fallopian duct
(c) uterus
(d) vagina
Answer: (c) uterus
In simple words: After fertilization, the embryo travels to the uterus where it embeds itself into the uterine wall, a process called implantation.

🎯 Exam Tip: The uterus is the site of embryo implantation and fetal development, a key concept in human reproduction.

 

e. ............type of reproduction occurs without fusion of gametes.
(a) Asexual
(b) sexual
(c) Fertilization
(d) Gamete formation
Answer: (a) Asexual
In simple words: Asexual reproduction involves only one parent and does not require the fusion of gametes to produce offspring.

🎯 Exam Tip: Distinguish between sexual and asexual reproduction by focusing on the involvement of gametes and genetic recombination.

 

f. Body breaks up into several fragments and each fragment begins to live as a new individual.
This is ............ type of reproduction.
(a) regeneration
(b) fragmentation
(c) binary fission
(d) budding
Answer: (b) fragmentation
In simple words: Fragmentation is a type of asexual reproduction where an organism's body breaks into pieces, and each piece develops into a new, complete individual.

🎯 Exam Tip: Understand the specific characteristics of different asexual reproduction methods, such as fragmentation, budding, and binary fission, to correctly identify them.

 

g. Pollen grains are formed by division in locules of anthers.
(a) meiosis
(b) mitosis
(c) amitosis
(d) binary
Answer: (a) meiosis
In simple words: Pollen grains, which contain male gametes, are produced through meiosis within the anthers of a flower.

🎯 Exam Tip: Recall that meiosis is the process of cell division that produces haploid gametes (like pollen grains) in sexually reproducing organisms.

 

Question 3. Complete the paragraph with the help of words given in the bracket:
(Luteinizing hormone, endometrium of uterus, follicle stimulating hormone, estrogen, progesterone, corpus luteum)
Growth of follicles present in the ovary occurs under the effect of ............ This follicle secretes estrogen. Ovarian follicle along with oocyte grows/regenerates under the effect of estrogen. Under the effect of ..............., fully grown up follicle bursts, ovulation occurs and ............ is formed from remaining part of follicle. It secretes ............ and ............ Under the effect of these hormones, glands of ............ are activated and it becomes ready for implantation.
Answer: Growth of follicles present in the ovary occurs under the effect of follicle stimulating hormone. This follicle secretes estrogen. Ovarian follicle along with oocyte grows/regenerates under the effect of estrogen. Under the effect of Luteinizing hormone, fully grown up follicle bursts, ovulation occurs and corpus luteum is formed from remaining part of follicle. It secretes estrogen and progesterone. Under the effect of these hormones, glands of endometrium of uterus are activated and it becomes ready for implantation.
In simple words: This paragraph describes the hormonal regulation of the ovarian and uterine cycles during the menstrual cycle, highlighting the roles of FSH, LH, estrogen, and progesterone in follicle development, ovulation, corpus luteum formation, and preparing the uterus for implantation.

🎯 Exam Tip: Understanding the sequence of events and the specific hormones involved in the menstrual cycle is key. Each hormone has a distinct role that builds upon the previous step.

 

Question 4. Answer the following questions short.
a. Explain with examples types of asexual reproduction in unicellular organism.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): अमीबा में द्विखंडन की प्रक्रिया को दर्शाया गया है। इसमें एक जनक कोशिका विभाजित होकर दो समान पुत्री कोशिकाएं बनाती है, जिसमें केंद्रक और कोशिकाद्रव्य दोनों का विभाजन होता है।
ℹ️ चित्र व्याख्या (Diagram Explanation): पैरामीशियम में अनुप्रस्थ द्विखंडन को दर्शाया गया है। इसमें पैरामीशियम की शरीर की अनुप्रस्थ दिशा में विभाजन होता है, जिससे दो समान पुत्री पैरामीशियम बनते हैं।
ℹ️ चित्र व्याख्या (Diagram Explanation): यूग्लीना में अनुदैर्ध्य द्विखंडन की प्रक्रिया दिखाई गई है। इसमें कोशिका का विभाजन लंबाई की दिशा में होता है, जिससे दो पुत्री यूग्लीना कोशिकाएं बनती हैं। There are different methods of asexual reproduction in different unicellular animals.
(1) Binary fission: The process in which the parent cell divides to form two similar daughter cells is binary fission. It takes place either by mitosis or amitosis. When there are favourable conditions and abundant food supply then the organisms undergo binary fission. Prokaryotes, Protists and eukaryotic 5 cell-organelle like mitochondria and chloroplasts perform binary fission.
Based on axis of fission there are three subtypes of binary fission.
(a) Simple binary fission: The plane of division is not definite, it can be in any direction due to lack of specific shape as in Amoeba.
(b) Transverse binary fission: The plane of J division is transverse, as in Paramoecium.
(c) Longitudinal binary fission: The plane of division is in length-wise direction as in Euglena.
(2) Multiple fission:
ℹ️ चित्र व्याख्या (Diagram Explanation): अमीबा में बहुविखंडन की प्रक्रिया को दर्शाया गया है। प्रतिकूल परिस्थितियों में, अमीबा एक सुरक्षात्मक पुटी (सिस्ट) बनाता है, जिसके अंदर केंद्रक और कोशिकाद्रव्य कई बार विभाजित होकर अनेक छोटी अमीब्यूली बनाते हैं। अनुकूल परिस्थितियां आने पर ये अमीब्यूली पुटी से बाहर निकलते हैं।
During unfavourable conditions when there is lack of food, multiple fission is shown by amoeba. Amoeba forms protective covering and becomes encysted. Inside the cyst, amoeba undergoes repeated nuclear division. This is followed by cytoplasmic divisions. Many amoebulae are formed which remain dormant inside the cyst. When favourable conditions reappear, they come out by breaking the cyst.
(3) Budding in yeast:
ℹ️ चित्र व्याख्या (Diagram Explanation): यीस्ट में मुकुलन की प्रक्रिया को दर्शाया गया है। इसमें जनक यीस्ट कोशिका की सतह पर एक छोटा उभार (मुकुल) बनता है, जिसमें केंद्रक विभाजित होकर एक पुत्री केंद्रक प्रवेश करता है। यह मुकुल बड़ा होकर जनक कोशिका से अलग होकर नया यीस्ट बनाता है।
Yeast is unicellular fungus that performs budding. The parent cell produces two daughter nuclei by mitotic division. This results in a small bulgingbud on the surface of parent cell. One daughter nucleus enters the bud. It then grows and upon becoming big it separates from the parent cell to have independent life as new yeast cell.
In simple words: Unicellular organisms reproduce asexually through various methods like binary fission (e.g., Amoeba, Paramoecium, Euglena), where a single cell divides into two, or multiple fission (e.g., Amoeba in unfavorable conditions), where a cell divides into many. Budding (e.g., Yeast) involves forming an outgrowth that detaches to become a new organism.

🎯 Exam Tip: When explaining asexual reproduction in unicellular organisms, clearly define each type (binary fission, multiple fission, budding) and provide a relevant example for each to illustrate your points effectively.

 

b. Explain the concept of IVF.
Answer:
(1) IVF means In Vitro Fertilization (IVF)
(2) This is the technique in the modern medical field where childless couples can be blessed by their own child.
(3) IVF technique is used for childless couples who are faced with problems such as less sperm count, obstacles in oviduct, etc.
(4) The IVF technique is done by removing the oocyte from the mother and artificially fertilizing by the sperms collected from father. This fertilization is done in a test-tube. Thus it is also called test tube baby. The embryo formed is implanted in uterus of real mother or a surrogate mother at appropriate time.
In simple words: IVF, or In Vitro Fertilization, is a medical technique that helps childless couples conceive by fertilizing an egg with sperm outside the body in a lab, then implanting the resulting embryo into a mother's uterus. It's used for issues like low sperm count or blocked fallopian tubes.

🎯 Exam Tip: When describing IVF, clearly state what the acronym stands for, explain the main steps (oocyte retrieval, external fertilization, embryo implantation), and mention the types of couples it assists.

 

c. Which precautions will you follow to maintain the reproductive health?
Answer: About reproductive health one should have scientific and authentic information. The cleanliness of body is very essential but keeping the mind clean is also important to maintain good reproductive health. One should be careful about sexual relationships. These things should not be experimented in young age. Mistakes committed like these can change the sexual health forever. The cleanliness and hygiene during menstruation, the cleanliness of genitals and other private parts are the aspects of personal hygiene. When living in a society, one should always be away from cross-infections of venereal type.
In simple words: Maintaining reproductive health involves seeking accurate information, practicing good personal hygiene, especially of genitals, avoiding risky sexual behaviors, and ensuring mental well-being to prevent infections and complications.

🎯 Exam Tip: Focus on a holistic approach to reproductive health, including physical hygiene, informed choices, and mental well-being, to provide a comprehensive answer.

 

d. What is menstrual cycle? Describe it in brief.
Answer:
- Menstrual cycle is the events of cyclic changes that takes place with the interval of 28 to 30 days in mature woman.
- Hormones from pituitary, FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone) and hormones from ovary, estrogen and progesterone control the menstrual cycle.
- Due to influence of FSH, the ovarian follicle grows along with the oocyte that is present in it.
- This growing follicle produces estrogen.
- Under the influence of estrogen, the uterine inner layer called endometrium grows or regenerates. In the meantime the development of follicle is completed.
- LH from pituitary stimulates the bursting of ovarian follicle and releases the mature oocyte out of the follicle and the ovarian wall. This process is called ovulation.
- The empty ovarian follicle after the ovulation becomes corpus luteum. Corpus luteum produces hormone progesterone.
- Under the influence of progesterone, the glands from uterine endometrium start secreting. The oocyte if fertilized is implanted over this endometrium.
- If oocyte is not fertilized, the corpus luteum becomes a degenerate body called corpus albicans. The corpus albicans cannot secrete estrogen and progesterone.
- Due to lack of these hormones, the endometrial layer of the uterus collapses. The tissue debris, along with unfertilized egg is given out through the vagina as menstrual flow. This results in bleeding for about 5 days.
- If woman is not pregnant, then this menstrual cycle keeps on repeating with regularity.
In simple words: The menstrual cycle is a regular series of hormonal and physiological changes in mature women, typically lasting 28-30 days, that prepares the uterus for pregnancy. It involves follicle growth, ovulation (release of an egg), and changes in the uterine lining, ending in menstruation if no fertilization occurs.

🎯 Exam Tip: A good description of the menstrual cycle should cover the key phases (follicular, ovulatory, luteal, menstrual), the main hormones involved (FSH, LH, estrogen, progesterone), and the changes occurring in both the ovary and the uterus.

 

Question 5. In case of sexual reproduction, newborn show similarities about characters. Explain this statement with suitable examples.
Answer:
(1) Sexual reproduction occurs due to two different gametes. One male gamete is from father while the other female gamete is from mother.
(2) Both the gametes are produced by meiosis.
(3) When the gametes unite it is called process of fertilization which produces diploid zygote.
(4) Due to the chromosomes of parents, their DNA pass to the next generation through such fertilization. Therefore, the characters of newborn show similarities with parents.
In simple words: Newborns in sexual reproduction inherit genetic material from both parents through the fusion of male and female gametes, which are formed by meiosis. This combination of parental chromosomes in the zygote ensures that the offspring display a mix of traits, leading to similarities with both parents.

🎯 Exam Tip: Emphasize the roles of meiosis (gamete formation), fertilization (zygote formation), and chromosome inheritance in ensuring genetic similarities between offspring and parents in sexual reproduction.

 

Question 6. Sketch the labelled diagrams.
a. Human male reproductive system.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव नर प्रजनन प्रणाली को दर्शाता है। इसमें मूत्राशय, शुक्राशय, प्रोस्टेट ग्रंथि, काउपर ग्रंथि, मूत्रमार्ग, मूत्रजनन नलिका, एपिडिडाइमिस, स्क्रोटम, वृषण, स्खलन नलिका, वास डेफेरेंस और लिंग जैसे प्रमुख अंगों को लेबल किया गया है।
In simple words: The human male reproductive system includes testes, ducts like vas deferens, and glands such as prostate and seminal vesicles, all contributing to sperm production, maturation, and delivery for reproduction.

🎯 Exam Tip: For diagrams, ensure all major parts are clearly labeled and their relative positions are accurate. Practice drawing and labeling key systems for quick recall during exams.

 

b. Human female reproductive system.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव मादा प्रजनन प्रणाली को दर्शाता है। इसमें डिंबवाहिनी (फेलोपियन ट्यूब), अंडाशय, गर्भाशय और योनि जैसे मुख्य अंगों को स्पष्ट रूप से दर्शाया गया है।
In simple words: The human female reproductive system comprises ovaries, fallopian tubes, uterus, and vagina, responsible for egg production, fertilization, fetal development, and childbirth.

🎯 Exam Tip: When reproducing diagrams of biological systems, precise labeling of each component and understanding its function are critical for an accurate representation.

 

c. Flower with its reproductive organs.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक फूल के अनुदैर्ध्य खंड को दिखाता है, जिसमें उसके प्रजनन अंग दर्शाए गए हैं। इसमें वर्तिकाग्र, वर्तिका, अंडाशय (स्त्रीकेसर का हिस्सा), दल, परागकोष, तंतु (पुंकेसर का हिस्सा) और बाह्यदल जैसे भाग लेबल किए गए हैं। यह फूल की आंतरिक संरचना और प्रजनन भागों को समझाता है।
In simple words: A flower's reproductive organs include the carpel (stigma, style, ovary) for female reproduction and the stamen (anther, filament) for male reproduction, along with petals and sepals, all essential for plant sexual reproduction.

🎯 Exam Tip: Diagrams of plant reproductive organs should clearly distinguish between male (stamen - anther, filament) and female (carpel - stigma, style, ovary) parts, along with accessory whorls like petals and sepals.

 

d. Menstrual cycle.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र महिलाओं में मासिक धर्म चक्र को दर्शाता है, जिसमें अंडाशय और गर्भाशय में होने वाले चक्रीय परिवर्तनों को दिखाया गया है। इसमें हाइपोथैलेमस से GnRH, पीयूष ग्रंथि से FSH और LH, और अंडाशय से एस्ट्रोजन व प्रोजेस्टेरोन हार्मोन की भूमिका, साथ ही अंडाशय में कूपों के विकास, अंडोत्सर्ग, कॉर्पस ल्यूटियम का निर्माण और गर्भाशय के एंडोमेट्रियम की मोटाई में परिवर्तन को 28-दिन के चक्र में दिखाया गया है।
In simple words: The menstrual cycle diagram illustrates the synchronized hormonal fluctuations from the hypothalamus and pituitary, alongside the corresponding changes in the ovary (follicle development, ovulation, corpus luteum) and uterus (endometrial growth and shedding) over approximately 28 days.

🎯 Exam Tip: When asked to sketch the menstrual cycle, include graphs or distinct phases showing hormonal levels (GnRH, FSH, LH, estrogen, progesterone), ovarian events (follicle maturation, ovulation, corpus luteum regression), and uterine changes (menstruation, proliferation, secretion) with proper timing.

 

Question 7. Give the names.
a. Hormones related with male reproductive system.
Answer: Follicle stimulating hormone and ICSH or Luteinizing hormone secreted by pituitary gland, testosterone secreted by testis.
In simple words: The main hormones involved in the male reproductive system are Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH or ICSH), and Testosterone, regulating sperm production and male characteristics.

🎯 Exam Tip: Clearly list the pituitary hormones and the gonadal hormone, specifying their source to demonstrate complete understanding.

 

b. Hormones secreted by ovary of female reproductive system.
Answer: Estrogen and progesterone.
In simple words: The ovaries in the female reproductive system primarily secrete estrogen and progesterone, which are crucial for regulating the menstrual cycle and supporting pregnancy.

🎯 Exam Tip: Remember the two primary hormones, estrogen and progesterone, and their origin (ovaries) for female reproductive physiology questions.

 

c. Types of twins.
Answer: Monozygotic twins, Siamese twins and Dizygotic twins.
In simple words: The three main types of twins are monozygotic (identical, from one zygote), dizygotic (fraternal, from two separate zygotes), and Siamese (conjoined, a rare form of monozygotic).

🎯 Exam Tip: When asked for types of twins, listing the key categories-monozygotic, dizygotic, and siamese-is sufficient. Briefly knowing their origin helps differentiate them.

 

d. Any two sexual diseases.
Answer: Gonorrhea and Syphilis.
In simple words: Two common sexually transmitted infections are Gonorrhea and Syphilis, both caused by bacteria and spread through sexual contact.

🎯 Exam Tip: Be able to name common STIs (Sexually Transmitted Infections) and their causes or general symptoms, as these are important public health topics.

 

e. Methods of family planning.
Answer: Copper T, condoms, oral contraceptive pills.
In simple words: Family planning methods include barrier methods like condoms, hormonal methods such as oral contraceptive pills, and intrauterine devices like Copper T, all aimed at preventing unwanted pregnancies.

🎯 Exam Tip: When listing family planning methods, include examples from different categories (barrier, hormonal, IUD) for a comprehensive answer.

 

Question 8. Gender of child is determined by the male? partner of couple. Explain with reasons whether this statement is true or false.
(OR)
"A couple shall have a male child or female child totally depends upon husband”. Prove truthfulness of this statement with scientific reason.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख मानव में लिंग निर्धारण की प्रक्रिया को दर्शाता है। इसमें पिता (नर) से उत्पन्न होने वाले दो प्रकार के शुक्राणु (22+X या 22+Y) और माता (मादा) से उत्पन्न होने वाले एक प्रकार के अंडाणु (22+X) दिखाए गए हैं। शुक्राणु के प्रकार के आधार पर, यह दिखाता है कि कैसे 22+X शुक्राणु 22+X अंडाणु के साथ मिलकर पुत्री (44+XX) बनाता है, जबकि 22+Y शुक्राणु 22+X अंडाणु के साथ मिलकर पुत्र (44+XY) बनाता है।
(1) The statement Gender of child is determined by the male partner of couple is true.
(2) It is clearly seen from the diagram that there are two types of sperms produced by males. One sperm has a X chromosome while the other has a Y chromosome, apart from autosomes. The mother on the other hand has all X bearing oocytes. Thus the sperm that fertilizes the oocyte decides the sex of the child.
(3) If X bearing sperm fertilizes the oocyte, daughter is born and when Y bearing sperm fertilizes the oocyte, son is born.
(4) Thus father or male partner is responsible for the determination of the sex.
In simple words: The gender of a child is indeed determined by the male partner because males produce two types of sperm (X and Y chromosomes), while females produce only one type of egg (X chromosome). The specific sperm (X or Y) that fertilizes the egg dictates whether the child will be female (XX) or male (XY).

🎯 Exam Tip: When explaining sex determination, clearly state the chromosomal contribution from both parents and how the male's sperm ultimately determines the offspring's gender.

 

Question 9. Explain asexual reproduction in plants.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र पौधों में अलैंगिक प्रजनन के विभिन्न तरीकों को दर्शाता है। इसमें शकरकंद (Sweet Potato) में जड़ों द्वारा, ब्रायोफिलम (Bryophyllum) में पत्तियों द्वारा, और आलू (Potato) में तने के भूमिगत शाखाओं और कलिकाओं (आंखों) द्वारा वानस्पतिक प्रवर्धन को स्पष्ट रूप से चित्रित किया गया है।
- Vegetative propagation is the method of asexual reproduction in plants.
- It takes place with the help of vegetative parts like root, stem, leaf and bud.
- Potato, suran (Amorphophallus) and other tubes propagate with the help of 'eyes' which are buds. These eyes are present on the stem tubers.
- In case of plants like sugarcane and grasses, buds present on nodes perform vegetative propagation.
- Plants like Bryophyllum performs vegetative propagation with the help of buds present on leaf margin.
In simple words: Asexual reproduction in plants, often called vegetative propagation, involves new plants growing from vegetative parts like roots, stems, or leaves, without seeds or spores. Examples include potato 'eyes' (buds on stem tubers), sugarcane nodes, and Bryophyllum leaf margins.

🎯 Exam Tip: Focus on explaining vegetative propagation as the primary form of asexual reproduction in plants, providing diverse examples from roots, stems, and leaves to illustrate the concept.

 

Question 10. Modern techniques like surrogate mother, sperm bank and IVF technique will help the human beings. Justify this statement.
Answer:
(1) Some couples want a child but they are not able to bear one due to various problems either in mother or in father. In such cases modern techniques such as IVF, surrogacy and sperm bank are useful in conceiving a child.
(2) These methods are as follows:
(i) Surrogacy: In woman if there is problem regarding the implantation of embryo in uterus, then help of another women is taken. This women is called surrogate mother.
Oocyte from real mother is taken out and fertilized with sperms collected from her husband. These gametes are fertilized outside in a test-tube and then the fertilized zygote is implanted in the surrogate mother.
(ii) In Vitro Fertilization (IVF) is done when there are problems like less sperm count or obstacles in oviduct. In IVF, fertilization is done in the test-tube. The embryo formed is implanted in uterus of woman for further growth.
(iii) Sperm bank: If man has problems with the sperm production, then the sperms are collected from the sperm bank. Sperm bank is the place where the donor's donate the sperms and such sperms are kept stored. The donor's identity is kept secret and he should also be physically and medically fit person.
In simple words: Modern reproductive technologies like surrogacy, sperm banks, and IVF offer solutions for couples facing infertility by enabling embryo implantation in a surrogate, providing donor sperm, or facilitating external fertilization, thus helping them achieve parenthood.

🎯 Exam Tip: When justifying the importance of modern techniques, clearly define each method (surrogacy, sperm bank, IVF), explain the specific infertility issues they address, and highlight their role in assisting childless couples.

 

Question 10. Modern techniques like surrogate mother, sperm bank and IVF technique will help the human beings. Justify this statement.
Answer:(1) Some couples want a child but they are not able to bear one due to various problems either in mother or in father. In such cases modern techniques such as IVF, surrogacy and sperm bank are useful in conceiving a child. (2) These methods are as follows: (i) Surrogacy: In woman if there is problem regarding the implantation of embryo in uterus, then help of another women is taken. This women is called surrogate mother. Oocyte from real mother is taken out and fertilized with sperms collected from her husband. These gametes are fertilized outside in a test-tube and then the fertilized zygote is implanted in the surrogate mother. (ii) In Vitro Fertilization (IVF) is done when there are problems like less sperm count or obstacles in oviduct. In IVF, fertilization is done in the test-tube. The embryo formed is implanted in uterus of woman for further growth. (iii) Sperm bank: If man has problems with the sperm production, then the sperms are collected from the sperm bank. Sperm bank is the place where the donor's donate the sperms and such sperms are kept stored. The donor's identity is kept secret and he should also be physically and medically fit person.
In simple words: Modern reproductive techniques like IVF, surrogacy, and sperm banks offer solutions for childless couples facing various fertility challenges by enabling fertilization outside the body, implantation in a surrogate, or using donor sperm. These methods help individuals achieve parenthood.

🎯 Exam Tip: Focus on explaining each technique (IVF, surrogacy, sperm bank) individually and their respective applications for different causes of infertility.

 

Question 11. Explain sexual reproduction in plants.
(OR)
Explain double fertilization in plants.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एंजियोस्पर्म में दोहरा निषेचन (Double Fertilization) प्रक्रिया को दर्शाता है। इसमें दिखाया गया है कि कैसे एक पराग कण (pollen grain) पराग नली (pollen tube) बनाता है, जो अंडाशय (ovary) तक पहुँचती है। इस प्रक्रिया में नर युग्मक (male gametes) अंडा कोशिका (egg cell) और ध्रुवीय नाभिक (polar nuclei) के साथ मिलकर भ्रूण (embryo) और एंडोस्पर्म (endosperm) बनाते हैं। - Plants reproduce sexually with the help of flowers. - Androecium and gynoecium are male and female parts of the flowers respectively. - In the carpel, the ovule undergoes meiosis and forms embryo sac. - A haploid egg cell and two haploid polar nuclei are present in each embryo sac. - The pollen grains from the anther reach the stigma of flower by the process of pollination. They germinate here on the stigma. - As a result of germination, long pollen tube and two male gametes are formed. - The pollen tube travels through the style of flower and the male gametes present in the pollen tube are transferred till the embryo sac in ovary. Upon reaching there, tip of the pollen tube bursts releasing two male gametes in embryo sac. - One male gamete unites with the egg cell and forms zygote. While other male gamete unites with two polar nuclei forming the endosperm. - Because there are two nuclei participating in this process, therefore it is called double fertilization. - After fertilization ovule develops into seed and ovary forms a fruit. When the seed again gets favourable conditions, it can produce a new plant.
In simple words: Sexual reproduction in plants involves flowers, which contain male (androecium) and female (gynoecium) reproductive parts. Pollination leads to the formation of a pollen tube and male gametes. Double fertilization occurs when one male gamete fuses with the egg cell to form a zygote, and another fuses with two polar nuclei to form endosperm, leading to seed and fruit development.

🎯 Exam Tip: Remember to clearly define pollination and explain the two distinct fertilization events that contribute to the "double fertilization" process in angiosperms.

 

Activities: (Do it your self)

 

Question 1. Collect the official data about present and a decade old population of various Asian countries and plot a graph of that data. With the help of it, draw your conclusions about demographic changes.
Answer:
In simple words: This activity involves gathering population data for Asian countries from two different time periods, then visualizing this data using a graph to identify and analyze demographic changes over time.

🎯 Exam Tip: For data collection and analysis tasks, ensure your data sources are credible and your conclusions are directly supported by the plotted information.

 

Question 2. With the help of your teacher, compose and present a road show to increase the awareness about prenatal gender detection and gender bias.
Answer:
In simple words: This activity encourages creating and performing a road show with your teacher to educate the public about the issues of prenatal gender detection and the societal problems caused by gender bias.

🎯 Exam Tip: When preparing for awareness campaigns, focus on clear, impactful messaging and engaging presentation methods to effectively communicate important social issues.

 

Can you recall? (Text Book Page No. 22)

 

Question 1. Which are the important life processes in living organisms?
Answer: The important life processes in living organisms are respiration, circulation, nutrition, excretion, sensation and response through nervous system.
In simple words: Essential life processes include breathing (respiration), blood flow (circulation), eating (nutrition), waste removal (excretion), and sensing/responding (sensation and nervous system).

🎯 Exam Tip: Listing the main physiological processes required for an organism's survival and function is key here.

 

Question 2. Which life processes are essential for production of energy required by body?
Answer: The oxidation of nutrients that are absorbed in body is done because of oxygen supplied to cells by respiratory and circulatory system. This helps in liberation of energy. Thus respiration, circulation and nutrition are the life processes that are essential for production of energy required by body.
In simple words: Respiration (oxygen intake), circulation (nutrient and oxygen transport), and nutrition (food intake) are vital for energy production as they facilitate the breakdown of nutrients with oxygen to release energy.

🎯 Exam Tip: Connect the intake of food and oxygen with their transport and breakdown to explain energy generation in the body.

 

Question 3. Which are main types of cell division? What are the differences?
Answer: The main types of cell division are mitosis and meiosis. In mitosis, the chromosome number remains the same. 2 daughter cells are obtained from one cell. In meiosis, the chromosome number is reduced to half. From one cell, four daughter cells are obtained.
In simple words: The two main types of cell division are mitosis (producing two identical daughter cells with the same chromosome number) and meiosis (producing four genetically diverse daughter cells with half the chromosome number).

🎯 Exam Tip: Clearly state the two types of cell division and highlight the key differences in chromosome number and number of daughter cells produced.

 

Question 4. What is the role of chromosomes in cell division?
Answer: Due to chromosomes, the DNA from parental cells enter into daughter cells. The hereditary, characters are transmitted to next generation by cell division.
In simple words: Chromosomes carry the genetic material (DNA) from parent cells to daughter cells during cell division, ensuring the transmission of hereditary characteristics to the next generation.

🎯 Exam Tip: Emphasize the role of chromosomes as carriers of genetic information and their importance in heredity during cell division.

 

Can you recall? (Text Book Page No. 22)

 

Question 1. What do we mean by maintenance of species?
Answer: Maintenance of species means a species undertakes successful reproduction and produces individuals of its own kind. This keeps the species existing on the earth.
In simple words: Maintenance of species refers to the ability of a species to successfully reproduce and create offspring, ensuring its continued existence on Earth.

🎯 Exam Tip: Define "maintenance of species" by linking it directly to successful reproduction and the perpetuation of the species.

 

Question 2. Whether the new organism is genetically exactly similar to earlier one that has produced it?
Answer: No. The new organism produced from the old one is not genetically exactly similar to the parents. In meiotic cell division there is crossing over in the homologous chromosomes. This produces genetic recombination. Thus the new organism is different from the earlier one. However, if the reproduction is of asexual type, then the young one is exactly similar to the parents.
In simple words: No, new organisms from sexual reproduction are not exactly similar due to genetic recombination during meiosis; however, in asexual reproduction, offspring are genetically identical to the parent.

🎯 Exam Tip: Differentiate between sexual and asexual reproduction regarding genetic similarity, highlighting meiosis and genetic recombination as factors for variation in sexual reproduction.

 

Question 3. Who determines whether the two organisms of a species will be exactly similar or not?
Answer: The type of reproduction, whether it is asexual or sexual, the type of crossing over, the extent of genetic recombination, etc. determine the similarity among the parent organisms and their, offspring. Based on this genetic recombination the two organisms of a species do not show exact similarity. However, in case of monozygotic twins there is exact similarity. In asexual reproduction to there is similarity.
In simple words: The type of reproduction (asexual or sexual), the occurrence of crossing over, and the degree of genetic recombination determine if organisms are exactly similar, with asexual reproduction and monozygotic twins resulting in exact similarity.

🎯 Exam Tip: Focus on the factors that influence genetic similarity-type of reproduction, crossing over, and recombination-and note exceptions like monozygotic twins.

 

Question 4. What is the relationship between the cell division and formation of new organism of same species by earlier existing organism?
Answer: In the process of reproduction, there is division of chromosomes. Due to cell division, the gametes are formed. The union of gametes produce new offspring. In sexual reproduction, all these processes take place due to cell division. In asexual reproduction too there is cell division. Growth of new organism also occurs due to cell division.
In simple words: Cell division is fundamental to reproduction; it forms gametes in sexual reproduction and directly creates new individuals in asexual reproduction. It is also crucial for the growth and development of the new organism.

🎯 Exam Tip: Emphasize that cell division (mitosis and meiosis) is the underlying biological mechanism for both the formation of gametes and the growth of new organisms, regardless of reproductive type.

 

Let's Think: (Text Book Page No. 26)

 

Question 1. What would have been happened if the male and female gametes had been diploid?
Answer: Diploid (2n) gametes if united, they will form 4n, i.e. tetraploid variety. Such zygote will show severe abnormality. The chromosome number will not be maintained.
In simple words: If male and female gametes were diploid, their fusion would result in a tetraploid (4n) zygote, leading to severe abnormalities and failure to maintain the characteristic chromosome number of the species.

🎯 Exam Tip: Highlight the consequence of incorrect chromosome numbers (polyploidy) and its effect on species viability and chromosomal stability.

 

Question 2. What would have been happened if any of the cells in nature had not been divided by meiosis?
Answer: If meiosis does not happen the gametes produced will be diploid. This will create abnormality.
In simple words: If meiosis did not occur, gametes would be diploid, and upon fertilization, the resulting zygote would have double the normal chromosome number, causing severe genetic abnormalities.

🎯 Exam Tip: Stress the role of meiosis in halving the chromosome number to ensure that sexual reproduction maintains a consistent diploid state across generations.

 

Can you recall? (Text Book Page No. 28)

 

Question 1. Which different hormones control the functions of human reproductive system through chemical coordination?
Answer: Pituitary gland secretes FSH and LH. LH is known as ICSH in males, as its function in the male body is different. From the gonads of male and female, hormones are secreted which are essential for male and female reproductive functions respectively. These hormones are testosterone secreted from testis in males and estrogen and progesterone secreted from the ovaries in females. Testosterone is essential for masculinity as well as for sperm production while female hormones are essential for changes in the female body leading to motherhood.
In simple words: The human reproductive system is controlled by pituitary hormones (FSH and LH) and gonadal hormones (testosterone in males, estrogen and progesterone in females), which regulate reproductive functions, secondary sexual characteristics, and processes like sperm production and preparation for motherhood.

🎯 Exam Tip: Identify the key hormones (FSH, LH, testosterone, estrogen, progesterone) and their origin (pituitary, testes, ovaries) and mention their primary roles in male and female reproduction.

 

Question 2. Which hormones are responsible for changes in human body occurring during onset of sexual maturity?
Answer: Testosterone in male body and estrogen in female body are responsible for maturity onset changes in human body.
In simple words: Testosterone is responsible for the onset of sexual maturity changes in males, while estrogen triggers these changes in females.

🎯 Exam Tip: Directly link testosterone to male puberty changes and estrogen to female puberty changes.

 

Question 3. Why has the Government of India enacted the law to fix the minimum age of marriage as 18 in girls and 21 in boys?
Answer: The full growth of female body is not completed till the age of 18. Till 18 years of age the physical and emotional maturity is not attained. Therefore, she is not suitable for marriage, sexual relationship and pregnancy. Similarly, boy attains complete growth only the age of 21. Therefore, to keep individuals and their progeny safe and healthy the Government of India enacted the law to fix the minimum age of marriage as 18 in girls and 21 in boys.
In simple words: The Indian government set the minimum marriage age at 18 for girls and 21 for boys to ensure physical and emotional maturity, preventing early marriages, pregnancies, and associated health risks for both individuals and their offspring.

🎯 Exam Tip: Emphasize the physiological and psychological maturity aspects for both genders and the impact on their health and offspring's well-being.

 

Can you recall? (Text Book Page No. 31)

 

Question 1. Which hormone is released from pituitary of mother once the foetal development is completed?
Answer: The hormone oxytocin is released from the posterior pituitary of mother once the foetal development is completed.
In simple words: Once fetal development is complete, the hormone oxytocin is released from the mother's posterior pituitary gland to initiate labor.

🎯 Exam Tip: Identify oxytocin as the key hormone responsible for initiating parturition (childbirth) and its origin from the pituitary gland.

 

Question 2. Under the effect of that hormone, which organ of the female reproductive system starts to contract and thereby birth process (parturition) is facilitated?
Answer: Due to oxytocin, uterus contracts involuntarily and the baby is expelled out. Thus initiation of birth process is possible due to contractions of uterus.
In simple words: Under the influence of oxytocin, the uterus undergoes involuntary contractions, which facilitates the birth process (parturition) by expelling the baby.

🎯 Exam Tip: Connect oxytocin's action directly to uterine contractions, which are essential for childbirth.

 

Use your brain power. (Text Book Page No. 24)

 

Question 1. Does the parent cell exist after asexual reproduction-fission?
Answer: In fission, the parent cell divides into two. This nucleus and cytoplasm, both are divided. Thus, parent cell does not exist any longer, it is converted into new cells.
In simple words: In asexual reproduction through fission, the parent cell divides completely to form two new daughter cells, meaning the original parent cell ceases to exist as a distinct entity.

🎯 Exam Tip: Understand that fission is a form of cell division where the parent organism becomes the daughter organisms, so the original "parent" entity no longer remains.

 

Choose the correct alternative and write that alphabet against the sub-question number:

 

Question 1. Pranav and Pritee are twins in your class. They belong to ........... twins type.
(a) monozygotic
(b) dizyotic
(c) siamese
(d) none of the above
Answer: (b) dizyotic
In simple words: Dizygotic twins develop from two separate fertilized eggs, so they can be of different genders, like Pranav and Pritee.

🎯 Exam Tip: Remember that dizygotic twins originate from two distinct zygotes, allowing for different genders and genetic makeup.

 

Question 2. Longitudinal binary fission is seen in ..............
(a) Paramoecium
(b) Euglena
(c) Amoeba
(d) Spirogyra
Answer: (b) Euglena
In simple words: Euglena reproduces through longitudinal binary fission, where the cell divides along its length.

🎯 Exam Tip: Associate specific organisms with their characteristic types of binary fission; Euglena performs longitudinal fission.

 

Question 3. Yeast cell performs asexual reproduction by ............
(a) fragmentation
(b) budding
(c) binary fission
(d) regeneration
Answer: (b) budding
In simple words: Yeast cells reproduce asexually through budding, where a small outgrowth develops and eventually detaches to form a new individual.

🎯 Exam Tip: Remember that budding is a common asexual reproductive method, specifically associated with yeast.

 

Question 4. Carrot and raddish undergoes ............. with the help of their roots.
(a) vegetative propagation
(b) fragmentation
(c) budding
(d) regeneration
Answer: (a) vegetative propagation
In simple words: Carrots and radishes reproduce asexually using their roots through a process called vegetative propagation.

🎯 Exam Tip: Identify vegetative propagation as the method of asexual reproduction involving plant parts like roots, stems, or leaves.

 

Question 5. Androecium and gynoecium are ............ whorl of the flower.
(a) accessory
(b) essential
(c) external
(d) internal
Answer: (b) essential
In simple words: The androecium (male reproductive part) and gynoecium (female reproductive part) are considered essential whorls of a flower because they are directly involved in reproduction.

🎯 Exam Tip: Classify floral whorls into essential (reproductive) and accessory (protective/attractive) for understanding flower structure and function.

 

Question 6. Flowers without stalk are called ........... flowers.
(a) stalkless
(b) sessile
(c) incomplete
(d) complete
Answer: (b) sessile
In simple words: Flowers that lack a stalk (pedicel) are referred to as sessile flowers.

🎯 Exam Tip: Know the botanical terms for flower structures, such as sessile for flowers lacking a pedicel.

 

Question 7. ............ on the inner surface of fallopian ducts (oviducts) push the egg towards uterus.
(a) Cilia
(b) Tentacles
(c) Flagella
(d) Fibres
Answer: (a) Cilia
In simple words: Cilia, tiny hair-like structures on the inner surface of the fallopian ducts, create a current that helps move the egg towards the uterus.

🎯 Exam Tip: Understand the role of cilia in the fallopian tubes for ovum transport, which is a crucial part of the female reproductive process.

 

Question 8. Pregnant mother supplies nourishment to her foetus through ............
(a) breasts
(b) uterus
(c) placenta
(d) ovaries
Answer: (c) placenta
In simple words: The placenta is the organ that forms during pregnancy to provide essential nourishment and oxygen to the developing fetus from the mother's blood.

🎯 Exam Tip: Identify the placenta as the primary organ for nutrient and waste exchange between mother and fetus during pregnancy.

 

Question 9. The length of a sperm is about ............. micrometers.
(a) 400
(b) 5
(c) 60
(d) 600
Answer: (c) 60
In simple words: A human sperm is typically about 60 micrometers long, a microscopic size enabling its motility towards the egg.

🎯 Exam Tip: Recall the approximate size of a sperm as a basic biological fact.

 

Question 10. Vegetative propagation is performed with the help of ........... in sweet potato.
(a) root
(b) stem
(c) leaf
(d) flower
Answer: (a) root
In simple words: In sweet potato, vegetative propagation, a form of asexual reproduction, occurs using its modified roots.

🎯 Exam Tip: Distinguish between different plant parts involved in vegetative propagation for specific examples like the sweet potato's root.

 

Question 11. Which of the following is not a unisexual flower?
(a) Coconut
(b) Papaya
(c) Gulmohar
(d) Maize
Answer: (c) Gulmohar
In simple words: Gulmohar flowers are bisexual, meaning they contain both male and female reproductive parts, unlike coconut, papaya, and maize which have unisexual flowers.

🎯 Exam Tip: Understand the difference between unisexual (male or female parts) and bisexual (both male and female parts) flowers, and know common examples of each.

 

Write whether the following statements are true or false, with the suitable reason:

 

Question 1. Absence of genetic recombination is an advantage whereas fast process is drawback of asexual reproductive method.
Answer: False. (Absence of genetic recombination is a drawback whereas fast process is advantage of asexual reproductive method.)
In simple words: This statement is false because the absence of genetic recombination is a disadvantage in asexual reproduction as it limits variation, while a fast reproductive process is actually an advantage.

🎯 Exam Tip: Clearly distinguish between advantages (e.g., speed, no mate needed) and disadvantages (e.g., lack of genetic diversity) of asexual reproduction.

 

Question 2. Prokaryotes show fission which occurs either by mitosis or amitosis.
Answer: True. (Prokaryotes show fission by both the methods, i.e. mitosis and amitosis.)
In simple words: This statement is true; prokaryotes reproduce through binary fission, which is a simpler form of cell division resembling both mitosis and amitosis.

🎯 Exam Tip: Remember that prokaryotic fission is distinct from eukaryotic mitosis/meiosis, though it shares characteristics with simpler forms of division.

 

Question 3. During favourable conditions multiple fission is performed by amoeba.
Answer: False. (During unfavourable conditions multiple fission is performed by amoeba.)
In simple words: This statement is false; Amoeba performs multiple fission specifically during unfavorable conditions to survive by forming a protective cyst.

🎯 Exam Tip: Differentiate between binary fission (favorable conditions) and multiple fission (unfavorable conditions) in Amoeba.

 

Question 4. Any encysted Amoeba or any other protist is called 'Cyst'.
Answer: True. (Cyst is the tough capsule like structure which keeps the protists dormant inside it. This helps the organisms to tide over unfavourable conditions.)
In simple words: This statement is true; a cyst is indeed a tough, protective capsule formed by encysted Amoeba or other protists, allowing them to survive unfavorable environmental conditions in a dormant state.

🎯 Exam Tip: Define "cyst" as a protective, dormant structure formed by certain organisms, especially protists, during harsh conditions.

 

Question 5. If the body of Sycon breaks up accidentally into only large and few fragments, then only each fragment develops into new Sycon.
Answer: False. (If the body of Sycon breaks up accidentally into many fragments, each fragment develops into new Sycon. Because the capacity to regenerate is very strong in poriferan Sycon, even a small piece of parent Sycon can give rise to entire new individual.)
In simple words: This statement is false because Sycon has a strong regenerative capacity, meaning even small fragments can develop into new individuals, not just large ones.

🎯 Exam Tip: Recognize that organisms with high regenerative capacity, like Sycon, can develop new individuals from multiple, even small, fragments.

 

Question 6. Pollen tube reaches the zygote via style.
Answer: False. (Pollen tube reaches the embryo sac via style. Later, double fertilization takes place and the zygote and endosperm are formed.)
In simple words: This statement is false; the pollen tube reaches the embryo sac within the ovule via the style, not the zygote itself, as the zygote forms after fertilization.

🎯 Exam Tip: Clarify the pathway of the pollen tube, noting it targets the embryo sac to deliver gametes, not a pre-existing zygote.

 

Question 7. There is glucose sugar in the semen.
Answer: False. (There is fructose sugar in the semen. Glucose is not present in semen.)
In simple words: This statement is false; semen primarily contains fructose, not glucose, as the main energy source for sperm.

🎯 Exam Tip: Differentiate between glucose and fructose, remembering fructose is the primary sugar in semen for sperm energy.

 

Question 8. Out of 2 - 4 million ova, approximately only 400 oocytes are released up to the age of menopause.
Answer: True. (During the reproductive span of the woman, from menarche to menopause only one oocyte per one month is released in the span of 30 to 35 years.)
In simple words: This statement is true; despite having millions of potential ova, a woman typically releases only about 400 oocytes during her entire reproductive lifespan, from menarche to menopause.

🎯 Exam Tip: Understand the vast difference between the initial number of oocytes and the much smaller number actually released during a woman's reproductive years.

 

Question 9. If the oocyte is fertilized, secretion of estrogen and progesterone stops completely.
Answer: False. (If the oocyte is not fertilized, there is no need of corpus luteum which secretes progesterone. In absence of conception, the progesterone is not needed, thus corpus luteum degenerates and forms corpus albicans.)
In simple words: This statement is false; if fertilization occurs, the corpus luteum continues to secrete estrogen and progesterone to maintain the pregnancy; these hormones only stop if fertilization does not happen.

🎯 Exam Tip: Remember that sustained secretion of progesterone and estrogen is crucial for maintaining pregnancy after fertilization, preventing the corpus luteum from degenerating.

 

Question 10. During menstruation there is need of rest along with special personal hygiene.
Answer: True. (During phase of menstruation there is pain and bleeding in woman. Her body is also susceptible for infections. There is weakness and hence she needs rest along with special personal hygiene.)
In simple words: This statement is true; during menstruation, women experience physical discomfort, bleeding, and increased susceptibility to infections, making rest and diligent personal hygiene essential for health and well-being.

🎯 Exam Tip: Emphasize the physiological reasons (pain, bleeding, infection risk, weakness) why rest and hygiene are important during menstruation.

 

Find the odd one out:

 

Question 1. Circulation, Excretion, Sensation, Reproduction.
Answer: Reproduction. (All others are processes necessary for survival of the individual.)
In simple words: Reproduction is the odd one out because while it ensures the survival of the species, circulation, excretion, and sensation are processes vital for the immediate survival of an individual organism.

🎯 Exam Tip: Differentiate between processes essential for individual survival (homeostasis) and those primarily for species continuation (reproduction).

 

Question 2. Budding in hydra, Regeneration, Binary fission, Fragmentation
Answer: Binary fission. (All others are processes of asexual reproduction in multicellular organisms.)
In simple words: Binary fission is the odd one out as it is a method of asexual reproduction primarily in unicellular organisms, whereas budding, regeneration, and fragmentation typically occur in multicellular organisms.

🎯 Exam Tip: Classify asexual reproduction methods by the type of organism they primarily occur in (unicellular vs. multicellular).

 

Question 3. Carrot, Radish, Potato, Sweet potato.
Answer: Potato. (All others are edible roots.)
In simple words: Potato is the odd one out because it is a modified stem (tuber), while carrot, radish, and sweet potato are modified roots.

🎯 Exam Tip: Understand the botanical classification of edible plant parts (e.g., stem vs. root) for common vegetables.

 

Question 4. Vas eferens, vas deferens, prostate gland, epididymis.
Answer: Prostate gland. (All others are duct systems in male reproductive system.)
In simple words: Prostate gland is the odd one out because it is an accessory gland, whereas the vas eferens, vas deferens, and epididymis are parts of the duct system in the male reproductive system.

🎯 Exam Tip: Differentiate between glandular structures and tubular/duct systems within the male reproductive anatomy.

 

Question 5. Prostate gland, Bartholin's gland, Cowper's gland, Epididymis.
Answer: Bartholin's glands. (All others are parts of male reproductive system.)
In simple words: Bartholin's glands are the odd one out as they are part of the female reproductive system, while the prostate gland, Cowper's gland, and epididymis are components of the male reproductive system.

🎯 Exam Tip: Categorize the given organs as either male or female reproductive system components.

 

Question 6. Stigma, style, pollen, ovary.
Answer: Pollen. (All others are parts of gynoecium.)
In simple words: Pollen is the odd one out because it is the male gametophyte, while the stigma, style, and ovary are all components of the gynoecium (female reproductive part) of a flower.

🎯 Exam Tip: Identify the components of the male (androecium/pollen) and female (gynoecium/stigma, style, ovary) reproductive structures in a flower.

 

Identify the correlation between the first two words and suggest the suitable words in the fourth place:

 

Question 1. Amoeba: Fission : : Hydra : ...........
Answer: Amoeba: Fission : : Hydra : Budding
In simple words: Amoeba reproduces by fission, and similarly, Hydra reproduces by budding.

🎯 Exam Tip: Understand and recall the specific asexual reproduction methods associated with common organisms like Amoeba and Hydra.

 

Question 2. Transverse binary fission : Paramoecium : : Longitudinal binary fission : ...........
Answer: Transverse binary fission : Paramoecium : : Longitudinal binary fission : Euglena
In simple words: Paramoecium undergoes transverse binary fission, while Euglena undergoes longitudinal binary fission.

🎯 Exam Tip: Distinguish between different orientations of binary fission (transverse, longitudinal, irregular) and their corresponding examples.

 

Question 3. Calyx: Sepals :: Corolla : ...........
Answer: Calyx : Sepals: : Corolla : Petals
In simple words: Just as sepals are the individual units of the calyx, petals are the individual units of the corolla.

🎯 Exam Tip: Know the collective terms (whorls) and their individual components for flower structures (e.g., calyx is made of sepals, corolla of petals).

 

Question 4. Accessory whorls : Calyx and corolla :: Essential whorls : ...........
Answer: Accessory whorls : Calyx and corolla : : Essential whorls : Androecium and gynoeciuin
In simple words: The calyx and corolla are accessory whorls, providing protection and attraction, while the androecium and gynoecium are essential whorls, directly involved in reproduction.

🎯 Exam Tip: Understand the functional classification of floral whorls into accessory (non-reproductive) and essential (reproductive).

 

Question 5. Bisexual flower: Hibiscus :: Unisexual flower : ...........
Answer: Bisexual flower : Hibiscus : : Unisexual flower : Papaya
In simple words: Hibiscus is an example of a bisexual flower (having both male and female parts), whereas papaya is an example of a unisexual flower (having only male or female parts).

🎯 Exam Tip: Provide examples for both bisexual (hermaphrodite) and unisexual (male or female) flowers.

 

Question 6. FSH : Development of oocyte : : LH : ...........
Answer: FSH : Development of oocyte : : LH : Ovulation
In simple words: FSH (Follicle Stimulating Hormone) promotes the development of the oocyte, while LH (Luteinizing Hormone) triggers ovulation, the release of the mature egg.

🎯 Exam Tip: Recall the specific roles of Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) in the female reproductive cycle.

 

Define the following/Give meanings of the following:

 

Question 1. Budding in yeast.
Answer: Budding in yeast: Budding is the asexual reproductive process in which a small bulge or bud appears on the surface of parent cell as seen in unicellular yeast.
In simple words: Budding in yeast is an asexual reproduction method where a small outgrowth, or bud, forms on the parent cell, grows, and eventually separates to become a new yeast cell.

🎯 Exam Tip: Define budding by describing the formation of an outgrowth on the parent cell that develops into a new individual, characteristic of yeast.

 

Question 2. Budding in hydra.
Answer: Budding in hydra: Budding in hydra is asexual reproductive process in which an outgrowth is formed by repeated divisions of regenerative cells of body wall called bud.
In simple words: Budding in Hydra is an asexual reproductive process where an outgrowth, or bud, forms on the parent's body wall due to repeated cell divisions, eventually developing into a new, independent Hydra.

🎯 Exam Tip: Explain budding in Hydra by focusing on the outgrowth development from the body wall, indicating it's a multicellular organism's asexual process.

 

Question 3. Regeneration.
Answer: Regeneration: Regeneration is the asexual reproduction in Planaria in which the body is broken up into two parts and resulting each part regenerates remaining part of the body.
In simple words: Regeneration is a form of asexual reproduction where an organism, like Planaria, can regrow entire lost body parts or develop into new complete individuals from fragments.

🎯 Exam Tip: Define regeneration as the ability to regrow lost body parts or form complete organisms from fragments, exemplified by Planaria.

 

Question 4. Fragmentation.
Answer: Fragmentation: Fragmentation is the asexual type of reproduction in which the body of parent organism breaks up into many fragments. Each fragment can start living independently.
In simple words: Fragmentation is an asexual reproduction method where a parent organism's body breaks into multiple pieces, and each piece develops into a new, independent individual.

🎯 Exam Tip: Describe fragmentation as the process where an organism breaks into parts, each capable of developing into a new organism.

 

Question 5. Vegetative propagation.
Answer: Vegetative propagation: Vegetative propagation is a type of asexual reproduction in plants that takes place with the help of vegetative parts like root, stem, leaf and bud.
In simple words: Vegetative propagation is an asexual reproduction method in plants where new plants grow from vegetative parts like roots, stems, leaves, or buds, without involving seeds or spores.

🎯 Exam Tip: Define vegetative propagation as asexual reproduction in plants using non-sexual parts like roots, stems, or leaves.

Question 6. Fertilization.
Answer: Fertilization: The process by which two haploid gametes unite to form a diploid zygote is called fertilization.
In simple words: Fertilization is when two haploid sex cells (gametes) combine to form a single diploid cell (zygote).

🎯 Exam Tip: Understanding the ploidy levels (haploid and diploid) is crucial for defining fertilization accurately.

Question 7. Pedicel.
Answer: Pedicel: The stalk of the flower which is for the support is called pedicel.
In simple words: The pedicel is simply the stem or stalk that supports an individual flower.

🎯 Exam Tip: Differentiate between pedicel (stalk of a single flower) and peduncle (main flower stalk of an inflorescence).

Question 8. Pollination.
Answer: Pollination: Transfer of pollen grains from anther to the stigma is called pollination.
In simple words: Pollination is the movement of pollen from the male part of a flower (anther) to the female part (stigma), initiating seed formation.

🎯 Exam Tip: Knowing the male and female reproductive parts of a flower is essential for explaining pollination.

Question 9. Self-Pollination.
Answer: Self-Pollination: Pollination involving only one flower or two flowers borne on same plant is called self-pollination.
In simple words: Self-pollination occurs when pollen from a flower's anther lands on its own stigma or the stigma of another flower on the same plant.

🎯 Exam Tip: Focus on the "same plant" aspect to distinguish self-pollination from cross-pollination.

Question 10. Cross-Pollination.
Answer: Cross-Pollination: Pollination involving two flowers borne on two plants of same species is cross-pollination.
In simple words: Cross-pollination is when pollen is transferred between flowers of two different plants of the same species.

🎯 Exam Tip: Emphasize "different plants of the same species" as the key differentiating factor for cross-pollination.

Question 11. Endosperm.
Answer: Endosperm: Endosperm is the nourishing substance formed by the union of second male gamete with two polar nuclei at the time of fertilization in plants.
In simple words: Endosperm is a nutrient-rich tissue that develops in seeds after fertilization, providing food for the growing embryo.

🎯 Exam Tip: Remember endosperm's primary function is nourishment and its formation involves the second male gamete.

Question 12. Embryo sac.
Answer: Embryo sac: There are many ovules in the ovary, the structure formed in each of the ovule by meiosis is called embryo sac.
In simple words: The embryo sac is the female gametophyte within the ovule of a plant, containing the egg cell and other nuclei essential for fertilization.

🎯 Exam Tip: Identify the embryo sac as the female gametophyte and its location within the ovule.

Question 13. Menopause.
Answer: Menopause: Stoppage of functioning of female reproductive system due to lack of synthesis of hormones due to advancing age is called menopause.
In simple words: Menopause is the natural biological end of a woman's reproductive life, marked by the cessation of menstrual periods and ovarian hormone production due to aging.

🎯 Exam Tip: Key terms for menopause are "stoppage of functioning," "lack of hormone synthesis," and "advancing age."

Question 14. Placenta.
Answer: Placenta: An organ developed in the uterus of the pregnant mother, through which the embryo is given nourishment is called placenta.
In simple words: The placenta is a temporary organ that connects the mother's uterus to the developing fetus, providing nutrients, oxygen, and waste removal.

🎯 Exam Tip: Focus on the placenta's role in nutrient and gas exchange between mother and fetus during pregnancy.

Question 15. Menstrual cycle.
Answer: Menstrual cycle: The repetitive changes at the interval of every 28-30 days in female reproductive system that take place after puberty, form menstrual cycle.
In simple words: The menstrual cycle is a monthly series of changes a woman's body goes through in preparation for a possible pregnancy, involving the growth and shedding of the uterine lining.

🎯 Exam Tip: Remember the periodicity (28-30 days) and the hormonal regulation of the menstrual cycle.

Question 16. Corpus luteum.
Answer: Corpus luteum: Corpus luteum is the secondary structure that is formed from empty ovarian follicle after ovulation. This corpus luteum produces progesterone and thereby maintains pregnancy.
In simple words: The corpus luteum is a temporary endocrine structure that forms in the ovary after ovulation, producing progesterone to support a potential pregnancy.

🎯 Exam Tip: Connect the corpus luteum's formation to ovulation and its key role in progesterone production for pregnancy maintenance.

Question 17. Corpus albicans.
Answer: Corpus albicans: Corpus albicans is the degenerate body which is formed from corpus luteum, if the ovum is not fertilized.
In simple words: The corpus albicans is the white, fibrous scar tissue that remains in the ovary after the corpus luteum degenerates if pregnancy does not occur.

🎯 Exam Tip: The corpus albicans indicates the regression of the corpus luteum when fertilization does not take place.

Question 18. Ovulation.
Answer: Ovulation: Bursting of mature ovarian follicle under the influence of hormones to release the oocyte is called ovulation.
In simple words: Ovulation is the process where a mature egg is released from the ovary, ready to be fertilized.

🎯 Exam Tip: Associate ovulation with the release of the oocyte from a mature follicle due to hormonal influence.

Question 19. IVF.
Answer: IVF: In Vitro Fertilization is the technique in which fertilization is brought about outside the female body but in the test-tube and the embryo is implanted in uterus of woman.
In simple words: IVF (In Vitro Fertilization) is a fertility treatment where eggs are fertilized by sperm outside the body in a laboratory, and the resulting embryos are then implanted into the uterus.

🎯 Exam Tip: Highlight "outside the body in a test-tube" and "embryo implanted in uterus" as the core aspects of IVF.

Question 20. Sperm bank.
Answer: Sperm bank: Sperm bank is the place where semen donated by the desired men is collected after their thorough physical and medical check-up and stored at sub-zero temperatures in sterile conditions.
In simple words: A sperm bank is a facility where sperm is collected from donors, screened, and then frozen for later use in assisted reproductive technologies.

🎯 Exam Tip: Remember the purpose of sperm banks: collection, storage (sub-zero), and availability of screened sperm for fertility treatments.

Name The Following/Give The Names:

Question 1. Different glands associated with male reproductive system.
Answer: Seminal vesicles, Prostate gland, Cowper's or bulbourethral glands.
In simple words: The seminal vesicles, prostate gland, and Cowper's glands are accessory glands in the male reproductive system that produce fluids contributing to semen.

🎯 Exam Tip: Be sure to list all three major accessory glands and their general function (contributing to semen volume and composition).

Question 2. Agents of pollination.
Answer: Biotic: Insects, birds, few animals.
Abiotic: Water and wind.
In simple words: Pollination agents are factors like insects, birds, other animals, water, or wind that transfer pollen from one flower to another.

🎯 Exam Tip: Classify pollination agents into biotic (living) and abiotic (non-living) categories with relevant examples for each.

Question 3. Components of semen.
Answer: Secretion of prostate gland seminal vesicles and Cowper's glands along with sperms.
In simple words: Semen is a fluid composed of sperm cells and secretions from the seminal vesicles, prostate gland, and Cowper's glands.

🎯 Exam Tip: The two main components of semen are sperm and the fluids from the accessory glands.

Question 4. Two accessory whorls in flower.
Answer: Calyx and corolla.
In simple words: The calyx (sepals) and corolla (petals) are the outer, non-reproductive parts of a flower, together known as accessory whorls.

🎯 Exam Tip: The calyx acts as the outermost protective layer for the flower bud.

Question 5. Two essential whorls in flower.
Answer: Androecium and gynoecium.
In simple words: The androecium (male reproductive part) and gynoecium (female reproductive part) are the essential whorls of a flower directly involved in sexual reproduction.

🎯 Exam Tip: Essential whorls are directly involved in producing gametes and enabling fertilization in a flower.

Question 6. The modern techniques in reproduction.
Answer: In Vitro Fertilization, Surrogate mother, Sperm bank.
In simple words: Modern reproductive techniques include In Vitro Fertilization (IVF), surrogacy, and sperm banks, offering solutions for fertility challenges.

🎯 Exam Tip: Focus on understanding what each modern technique (IVF, surrogacy, sperm bank) primarily addresses in reproductive challenges.

Question 7. Symptoms of gonorrhea.
Answer: Painful and burning sensation during urination, oozing of pus through penis and vagina, inflammation of urinary tract, anus, throat, eyes, etc.
In simple words: Symptoms of gonorrhea often include painful urination, discharge from genitals, and inflammation in various body parts like the urinary tract, throat, or eyes.

🎯 Exam Tip: Recognize that gonorrhea symptoms involve discomfort during urination and unusual discharge from reproductive organs.

Question 8. Symptoms of syphilis.
Answer: Occurrence of chancre (patches) on various parts of body including genitals, rash, fever, inflammation of joints, alopecia, etc.
In simple words: Syphilis symptoms can include chancres (painless sores) on genitals, rashes, fever, and joint inflammation, progressing through stages if untreated.

🎯 Exam Tip: The presence of chancres (sores) on genitals is a distinctive primary symptom of syphilis.

Write The Functions Of The Following Organs:

Question 1. Sporangium.
Answer: Storing the spores and releasing them by bursting.
In simple words: A sporangium is a specialized structure that produces and encloses spores, releasing them when mature for reproduction.

🎯 Exam Tip: The primary function of the sporangium is spore production and dispersal for asexual reproduction.

Question 2. Calyx.
Answer: Protection of inner whorls of the flower.
In simple words: The calyx, made of sepals, protects the developing bud and the inner reproductive parts of the flower.

🎯 Exam Tip: The calyx acts as the outermost protective layer for the flower bud.

Question 3. Corolla.
Answer: Attracting insects for pollination. Protecting inner whorls.
In simple words: The corolla, composed of petals, primarily attracts pollinators like insects with its color and scent, and also offers protection to the inner floral parts.

🎯 Exam Tip: Focus on the dual role of the corolla: attraction for pollination and protection of essential organs.

Question 4. Androecium.
Answer: Production of pollen grains, the male gametes of flower.
In simple words: The androecium, consisting of stamens, is the male reproductive part of a flower responsible for producing pollen grains containing male gametes.

🎯 Exam Tip: The androecium's main function is male gamete (pollen) production, crucial for plant reproduction.

Question 5. Gynoecium.
Answer: Production of female gametes of flower. Participating in production of fruits.
In simple words: The gynoecium, the female reproductive part of a flower, produces female gametes (ovules) and develops into the fruit after fertilization.

🎯 Exam Tip: Remember the gynoecium's role in producing female gametes and its transformation into fruit post-fertilization.

Question 6. Endosperm.
Answer: Nourishment of the growing embryo.
In simple words: The endosperm serves as a food reserve, providing essential nourishment to the developing plant embryo within the seed.

🎯 Exam Tip: The key function of endosperm is to provide nutrients for embryo development.

Question 7. Testis.
Answer: Production of sperms and male hormone-testosterone.
In simple words: Testes are the primary male reproductive organs responsible for producing sperm and the male hormone testosterone.

🎯 Exam Tip: The two main functions of the testis are gamete (sperm) production and hormone (testosterone) secretion.

Question 8. Scrotum.
Answer: Protection and temperature control of testis.
In simple words: The scrotum is a sac of skin that holds the testes outside the body, providing a cooler temperature essential for sperm production and protection.

🎯 Exam Tip: The scrotum's critical role is maintaining the optimal temperature for spermatogenesis, slightly lower than body temperature.

Question 9. Seminal vesicles.
Answer: Secretion of seminal fluid which forms major portion of semen. Nourishment of sperms.
In simple words: Seminal vesicles produce a fluid rich in fructose and other substances, which provides nourishment for sperm and contributes significantly to semen volume.

🎯 Exam Tip: Remember that seminal vesicle secretions are primarily for sperm nourishment and form a large part of seminal fluid.

Question 10. Penis.
Answer: Transferring of sperms to vagina at the time of intercourse. Release of urine at the time of urination.
In simple words: The penis is the male external reproductive organ responsible for copulation and the transfer of sperm, as well as for urination.

🎯 Exam Tip: The penis serves as both a reproductive organ (sperm delivery) and an excretory organ (urine release).

Question 11. Ovary.
Answer: Production of oocytes and female hormones - estrogen and progesterone.
In simple words: The ovaries are female reproductive glands that produce egg cells (oocytes) and essential female hormones like estrogen and progesterone.

🎯 Exam Tip: Ovaries have a dual function: producing female gametes and secreting key female reproductive hormones.

Question 12. Uterus.
Answer: Growth and development of foetus during pregnancy. Helping in parturition (childbirth) by contractions.
In simple words: The uterus is a muscular organ in the female reproductive system where a fertilized egg implants and the fetus develops during pregnancy, also contracting to expel the baby during childbirth.

🎯 Exam Tip: The uterus is crucial for embryonic development and childbirth through its muscular contractions.

Question 13. Fallopian tubes/ducts.
Answer: Transporting the released oocyte after ovulation to the uterus. Providing space for fertilization of oocyte by sperm. Conception is possible only when sperm and oocyte meet in the fallopian tube.
In simple words: Fallopian tubes (oviducts) transport the egg from the ovary to the uterus and are the typical site where fertilization occurs.

🎯 Exam Tip: The fallopian tubes are vital for both egg transport and serving as the common site for fertilization.

Question 14. Vagina.
Answer: Passage for copulation/intercourse. Birth canal. Passage for menstrual flow.
In simple words: The vagina is a muscular canal that serves as the birth canal, the passage for menstrual flow, and receives the penis during sexual intercourse.

🎯 Exam Tip: The vagina has multiple key roles: reproductive (copulation, birth canal) and excretory (menstrual flow).

Distinguish Between:

Question 1. Binary fission and Multiple fission.
Answer:
Binary fission:
1. Two new individuals are formed from one old individual at one time.
2. The division of nucleus and cytoplasm takes place initially.
3. The axis of division can be transverse, longitudinal or any one axis as it is in simple binary fission.
4. Formation of protective cyst does not take place.
5. Binary fission can be done during favourable period.
Multiple fission:
1. Many new individuals are formed from one old individual at one time.
2. Only nucleus divides initially followed by division of cytoplasm.
3. There is no exact axis for the fission.
4. Protective covering is formed around dividing amoebulae which is called cyst.
5. Multiple fission takes place only at the time of unfavourable period.
In simple words: Binary fission produces two offspring from one parent, typically in favorable conditions, while multiple fission creates many offspring, often within a protective cyst during unfavorable conditions.

🎯 Exam Tip: Focus on the number of offspring, initial division sequence, axis of division, cyst formation, and environmental conditions to differentiate between binary and multiple fission.

Question 2. Human male and Human female reproduction system.
Answer:
Human male reproductive system:
1. Testis are essential organs which are located outside the abdomen in the scrotal sacs.
2. There is common urethra through which urine and semen, are passed out.
3. Reproductive system of male continues to work even in old age.
4. Sperms or male gametes are produced by meiosis in the testis.
5. Sperms are produced in millions at one time.
6. Three accessory glands are associated with the male reproductive system.
7. Testis secrete testosterone which is essential male hormone.
In simple words: The male reproductive system typically involves external testes, a common urethra for urine and semen, and continuous reproductive capacity, producing millions of sperm and testosterone.

🎯 Exam Tip: For the male system, key points include external gonads, shared urinary/reproductive duct, and continuous gamete production.

Human female reproductive system:
1. Ovaries are essential organs which are located along with all other organs inside the lower abdomen.
2. Urethra and vagina are two separate openings that open to outside.
3. Reproductive system works only till menopause.
4. Oocytes or ova are produced by meiosis in the ovaries.
5. Only single oocyte is produced per month.
6. Only one gland is associated with female reproductive system.
7. Ovaries produce estrogen and progesterone which are essential female hormones.
In simple words: The female reproductive system features internal ovaries and uterus, separate openings for urethra and vagina, reproductive function ceasing at menopause, and cyclical production of a single oocyte and female hormones.

🎯 Exam Tip: For the female system, highlight internal gonads, separate ducts, reproductive cessation at menopause, and cyclical, limited gamete production.

Question 3. Monozygotic twins and Dizygotic twins.
Answer:
Monozygotic twins:
1. Two children developing from only one zygote are called monozygotic twins.
2. Monozygotic twins develop from same oocyte.
3. Gender of both the twins is same.
4. The monozygotic twins are genetically exactly alike.
Dizygotic twins:
1. Two children developing from two different zygotes are called dizygotic twins.
2. Dizygotic twins develop from two different oocytes.
3. Gender of both the twins can be same or can be different.
4. The dizygotic twins are genetically not exactly alike.
In simple words: Monozygotic twins result from a single zygote splitting, making them genetically identical and always the same gender, whereas dizygotic twins develop from two separate zygotes (two eggs fertilized by two sperm), resulting in genetic differences and potentially different genders.

🎯 Exam Tip: The core distinction lies in the number of zygotes (one for monozygotic, two for dizygotic) which dictates genetic similarity and gender outcomes.

Give Scientific Reasons:

Question 1. Individual developed by sexual reproduction always carry recombined genes of both the parents.
Answer:
• In sexual reproduction, the haploid male and female gametes are united to form diploid zygote.
• The zygote thus carries chromosomes of both parents which are transferred via male and female gametes.
• While producing gametes, there is meiosis in which genetic recombination takes place.
• Therefore, the individual developed by sexual reproduction always carry recombined genes of both the parents.
In simple words: Sexual reproduction involves the fusion of gametes from two parents, each contributing half of their genetic material, and meiosis during gamete formation ensures genetic recombination, leading to offspring with a unique mix of parental genes.

🎯 Exam Tip: Emphasize the role of meiosis (genetic recombination) and the fusion of gametes from two distinct parents in ensuring genetic diversity.

Question 2. Flower is the structural unit of sexual reproduction in plant.
Answer:
• Flower produces male and female gametes.
• For this purpose there are essential whorls of androecium and gynoecium.
• The double fertilization also takes place in flower.
• Therefore, flower is called the structural unit of sexual reproduction in plants.
In simple words: The flower is considered the reproductive unit because it contains the male (androecium) and female (gynoecium) parts necessary for producing gametes and facilitating the double fertilization process.

🎯 Exam Tip: The presence of both male and female reproductive structures (androecium and gynoecium) and the occurrence of double fertilization make the flower the primary site of sexual reproduction.

Question 3. Fertilization in plants is called double fertilization.
Answer:
• After pollination the pollen grains drop on the sticky stigma of the flower.
• They germinate here producing two male gametes and a long pollen tube.
• The male gametes travel through the pollen tube till they reach the embryo sac.
• Here the male gametes are released by bursting the pollen tube. One male gamete unites with the egg cell to form zygote while the second male gamete unites with two polar nuclei forming endosperm.
• In this way because two nuclei participate in the fertilization process, therefore it is called double fertilization.
In simple words: Plant fertilization is called "double fertilization" because two separate fusion events occur: one male gamete fuses with the egg cell to form the zygote, and another male gamete fuses with two polar nuclei to form the endosperm.

🎯 Exam Tip: Clearly identify the two distinct fusion events-zygote formation and endosperm formation-as the basis for "double fertilization."

Question 4. By the age of 45-50 women gets menopause.
Answer:
• By the age of 45-50, the secretion of hormones which control the functioning of the reproductive system is reduced gradually and then it stops.
• This causes end of menstrual cycle. This results into menopause.
In simple words: Women experience menopause around ages 45-50 because their ovaries gradually reduce and eventually stop producing reproductive hormones like estrogen and progesterone, leading to the cessation of menstrual cycles.

🎯 Exam Tip: The gradual decline and cessation of ovarian hormone production is the primary reason for menopause in women.

Question 5. Older mothers have greater chance of conceiving abnormal children.
Answer:
• In older women the menopausal age approaches.
• The oocytes, released from ovaries during this phase are not normal.
• Their meiotic cell division is abnormal and thus oocyte becomes abnormal too.
• If such abnormal oocytes are fertilized, the baby is born with many genetic problems, e.g. Down's syndrome or Turner's syndrome.
In simple words: Older mothers have a higher risk of conceiving abnormal children because as a woman ages, the quality of her oocytes declines, and there's an increased likelihood of abnormal meiotic cell division, leading to genetic disorders in the offspring.

🎯 Exam Tip: Focus on the declining quality of oocytes and increased risk of abnormal meiotic division in older women as the scientific reason for genetic anomalies.

Question 6. Indians should follow family planning for controlling the population.
Answer:
• There is severe population explosion in India. It has almost reached to 121 crores.
• This results into unemployment, decreasing per capita income and increasing loan, stress on natural resources, etc.
• Only by controlling population, the quality of life can be restored.
• Therefore, Indians should follow family planning for controlling the population.
In simple words: Family planning is essential in India to manage the high population growth, which strains resources, contributes to unemployment, and impacts the overall quality of life, making population control crucial for sustainable development.

🎯 Exam Tip: Connect population control directly to resource management, economic stability, and improving the quality of life in a densely populated country like India.

Answer The Following Questions In Short:

Question 1. How does reproduction take place in fungus Mucor?
Answer:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र फंगस म्यूकर में बीजाणु निर्माण द्वारा प्रजनन को दर्शाता है। इसमें हाइफा (फिलामेंट) से एक स्पोरैंगियोफोर ऊपर उठता है, जिसके शीर्ष पर गोलाकार स्पोरैंजियम होता है। स्पोरैंजियम के अंदर बीजाणु (स्पोर) विकसित होते हैं, और परिपक्व होने पर यह फटकर बीजाणुओं को मुक्त करता है, जो नई कॉलोनी बनाते हैं।
• Mucor reproduces asexually by spore formation.
• It has filamentous body that possess sporangia.
• When the spores are formed, the sporangia burst. The spores are released which settle down at suitable Places.
• They germinate in moist and warm place forming a new fungal colony.
In simple words: Mucor reproduces asexually through spore formation, where a sporangium produces and releases spores that germinate in favorable conditions to form new fungal colonies.

🎯 Exam Tip: Focus on the key structures (sporangia, spores) and the process (release, germination) for asexual reproduction in fungi like Mucor.

Question 2. What is the type of asexual reproduction shown in the diagram below?
Answer:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र स्पाइरोगाइरा में विखंडन द्वारा अलैंगिक प्रजनन को दर्शाता है। इसमें एक लंबा स्पाइरोगाइरा फिलामेंट कई छोटे-छोटे टुकड़ों में टूट जाता है, और प्रत्येक टुकड़ा एक नए, स्वतंत्र स्पाइरोगाइरा में विकसित हो जाता है।
Fragmentation in Spirogyra
Type of asexual reproduction shown in the diagram above is fragmentation in Spirogyra.
In simple words: The diagram illustrates fragmentation, an asexual reproduction method where an organism, like Spirogyra, breaks into several fragments, and each fragment develops into a new, independent individual.

🎯 Exam Tip: Identify fragmentation by the breakdown of the parent body into multiple parts, each capable of growing into a new organism.

Question 3. Describe the structure of a flower.
Answer:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक फूल के अनुदैर्ध्य काट को दर्शाता है, जिसमें उसके विभिन्न भाग प्रदर्शित हैं। इसमें बाहरी सुरक्षात्मक बाह्यदलपुंज (सेपल्स) और रंगीन दलपुंज (पेटल्स) दिख रहे हैं। आंतरिक रूप से, नर प्रजनन अंग पुंकेसर (एंथर और फिलामेंट सहित) और मादा प्रजनन अंग स्त्रीकेसर (स्टिग्मा, स्टाइल और अंडाशय सहित) स्पष्ट रूप से चित्रित हैं, जो फूल की पूर्ण संरचना को दर्शाते हैं।
(1) The structural unit of sexual reproduction in plants is flower. There are total four floral whorls. Of these, two are accessory floral whorls while two are essential floral whorls.
(2) Calyx and corolla are accessory whorls. They are protective in nature.
(3) Members of calyx are known as sepals. They are usually green in colour. They protect the inner whorls.
(4) The members of corolla are called petals. They can be of different colours.
(5) Androecium and gynoecium are essential whorls as they participate in sexual reproduction.
In simple words: A flower is composed of four main whorls: the outer protective calyx (sepals) and corolla (petals), and the inner essential reproductive whorls, the androecium (male stamens) and gynoecium (female pistil/carpels), all working together for plant reproduction.

🎯 Exam Tip: Describe the four floral whorls-calyx, corolla, androecium, and gynoecium-and their respective functions and components, categorizing them as accessory or essential.

(6) The male whorl androecium is made up of stamens. Each stamen has a filament with anther located at the upper end. In the anther there are four locules. Inside the locules the meiosis takes place forming pollen grains. During suitable time, the pollen grains are released from anther lobes.
(7) Gynoecium is made up of carpels, either in separate form or are united. Each carpel is formed of ovary at the basal end hollow 'style' and the stigma at the tip of style. There are one or many ovules inside the ovary.
(8) In bisexual flowers both androecium and gynoecium are located in the same flower, e.g. Hibiscus.
(9) In unisexual flowers, androecium is present in male flowers and gynoecium is present in the female flowers, e.g. Papaya.

Question 4. Describe the human male reproductive system.
Answer:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव नर प्रजनन प्रणाली को दर्शाता है। इसमें मूत्राशय, मूत्रवाहिनी, वास डेफेरेंस, प्रोस्टेट ग्रंथि, सेमिनल वेसिकल्स, काउपर ग्रंथि और अंडकोष जैसे प्रमुख अंग दिखाए गए हैं। अंडकोष शरीर के बाहर स्थित होते हैं, जो शुक्राणु उत्पादन के लिए आवश्यक तापमान बनाए रखते हैं, और पेनिस शुक्राणु हस्तांतरण के लिए बाहरी अंग है।
In human male reproductive system, the reproductive organs are as follows:
• Testes, different types of duct systems and glands.
• Testes are in pair. Each testis lies in the scrotum which lies outside to abdominal cavity.
In simple words: The human male reproductive system consists of testes (which produce sperm and testosterone), a series of ducts (for sperm transport), and accessory glands (seminal vesicles, prostate, Cowper's) that produce fluids to form semen.

🎯 Exam Tip: When describing the male reproductive system, include the primary organs (testes), the pathway for sperm, and the accessory glands and their contributions.

 

Question 6. What problems cause infertility in couple?

Answer:

• In woman if there are problems like irregularity in menstrual cycle, difficulties in oocyte production or implantation in uterus, obstacles in the oviduct, etc.
• In man if there are no sperms in the semen, slow movement of sperms, or anomalies in the sperms then he becomes sterile.
• But now with the help of advanced medical techniques these problems can be overcome and a childless couple can be parents.

In simple words: Infertility can stem from various issues in women, such as irregular cycles or problems with egg production/implantation, and in men, it can be due to low sperm count or abnormal sperm. However, modern medical advances offer solutions for many of these challenges, enabling childless couples to have children.

🎯 Exam Tip: When explaining infertility causes, ensure to cover both male and female factors and mention the role of modern medical techniques. This demonstrates a comprehensive understanding.

 

Question 7. Answer the following questions:

Answer:
(a) In our country, there seems to be lack of awareness regarding reproductive health. Why?
(a) There is lack of awareness about reproductive health among majority of people of our country. This is due to social customs, traditions, illiteracy, social taboo and shyness.
(b) Write the symptoms of disease gonorrhea.
(b) Symptoms of gonorrhea are as follows:
1. Painful burning during urination.
2. Oozing of pus through penis or vagina.
3. Inflammation of urinary tract, anus, throat, eyes, etc.
(c) What precautions will you take to maintain reproductive health?
(c) Precautions to maintain reproductive health are cleanliness and personal hygiene. Guarding against any sexual infections.

In simple words: Lack of reproductive health awareness in India is often due to social factors like customs, illiteracy, and shyness. Gonorrhea symptoms include painful urination, pus discharge, and inflammation in various areas. Maintaining reproductive health requires good personal hygiene and protection against sexually transmitted infections.

🎯 Exam Tip: For questions on reproductive health, clearly differentiate between social causes of lack of awareness, specific disease symptoms, and general preventive measures. Use bullet points for clarity in listing symptoms or precautions.

 

Question 8. If a piece of bread is kept in a container in moist place for 2-3 days, (1) What will you see? (2) Write scientific name and a character of the organism you may observe.

Answer:
(1) If a piece of bread is kept in moist container we can see growth of fungus on it.
(2) Fungi belonging to species Mucor is seen. It has filamentous body and sporangia. Sporangia burst open to spread spores. It has saprophytic mode of nutrition as it devoid of chlorophyll.

In simple words: Keeping bread in a moist environment for a few days will lead to the growth of fungus, specifically Mucor. This fungus has a thread-like body (filamentous), produces spores within sporangia that burst open for dispersal, and obtains nutrients by decomposing organic matter as it lacks chlorophyll.

🎯 Exam Tip: When describing observations, provide specific details like the type of organism (Mucor) and its key characteristics (filamentous, sporangia, saprophytic nutrition). This shows a deeper understanding beyond a general observation.

 

Write Short Notes On:

 

Question 1. Multiple fission.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र अमीबा में बहुविखंडन को दर्शाता है। इसमें प्रतिकूल परिस्थितियों में अमीबा एक सुरक्षात्मक पुटी बनाता है, जिसके अंदर केंद्रक और कोशिकाद्रव्य बार-बार विभाजित होकर कई छोटी अमीबूले बनाते हैं।
During unfavourable conditions when there is lack of food. multiple fission is shown by amoeba. Amoeba forms protective covering and becomes encysted. Inside the cyst, amoeba undergoes repeated nuclear division. This is followed by cytoplasmic divisions. Many amoebulae are formed which remain dormant inside the cyst. When favourable conditions reappear, they come out by breaking the cyst.

In simple words: Multiple fission is a type of asexual reproduction where an organism, like Amoeba, forms a protective cyst under unfavorable conditions. Inside this cyst, the nucleus divides repeatedly, followed by cytoplasmic divisions, producing many smaller daughter cells (amoebulae) that are released when conditions become favorable.

🎯 Exam Tip: For multiple fission, emphasize the role of unfavorable conditions, cyst formation, and the subsequent repeated nuclear and cytoplasmic divisions leading to numerous offspring. Clearly state the organism showing this process.

 

Question 2. Regeneration.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र प्लेनेरिया में पुनरुत्पादन की प्रक्रिया को दर्शाता है। इसमें दिखाया गया है कि यदि प्लेनेरिया को कई टुकड़ों में काट दिया जाए, तो प्रत्येक टुकड़ा अपने खोए हुए भागों को पुनर्जीवित करके एक पूर्ण नया प्लेनेरिया बना सकता है।
In developed animals like wall lizard the process of regeneration is used to restore the lost parts like tail or limbs. As the reproductive system is one of the fullfledged system in the body, the process of regeneration cannot be called type of reproduction.
But some primitive organisms such as Plarfaria use this method for procreation. Planaria breaks up its body into two parts. Each part has the ability to develop the lost part by process of regeneration. This forms two new Planaria.

In simple words: Regeneration is the ability to regrow lost body parts, as seen in lizards, but it is not true reproduction in complex animals. However, in simpler organisms like Planaria, fragmentation and subsequent regeneration of each piece into a complete individual serves as a method of asexual reproduction.

🎯 Exam Tip: Distinguish between regeneration as a repair mechanism (in higher animals) and as a reproductive method (in lower organisms like Planaria). Providing examples for both scenarios enhances the explanation.

 

Question 3. Seed germination.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र बीज अंकुरण की प्रक्रिया को दर्शाता है। इसमें दिखाया गया है कि कैसे एक बीज से एक नया पौधा निकलता है, जिसमें मूलांकुर (radicle) से जड़ और प्रांकुर (plumule) से तना और पत्तियाँ विकसित होती हैं।
Seed germination is the process in which the seed develops into a new plantlet. In the plants, after fertilization the ovule develops into seed and ovary turns into fruit. Seeds fallen on the ground due to bursting of the fruits start germinating. Only under favourable conditions in the soil, this germination takes place. The zygote present inside the seed uses food stored in endosperm of seed and hence develops further to produce a new plantlet.

In simple words: Seed germination is the process where a dormant seed develops into a new plantlet under favorable environmental conditions. The embryo within the seed, utilizing stored food from the endosperm, grows its root (radicle) and shoot (plumule) to establish a new plant.

🎯 Exam Tip: Explain seed germination as a post-fertilization event where the ovule becomes the seed and the ovary becomes the fruit. Highlight the necessity of favorable conditions and the role of stored food in the endosperm for embryo development.

 

Question 4. Budding in hydra.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र हाइड्रा में मुकुलन (budding) द्वारा अलैंगिक प्रजनन को दर्शाता है। इसमें एक जनक हाइड्रा की शारीरिक दीवार पर एक छोटा मुकुल बनता है, जो धीरे-धीरे विकसित होकर एक नए छोटे हाइड्रा में बदल जाता है और फिर अलग होकर स्वतंत्र जीवन जीता है।
In multicellular organisms asexual reproduction by budding is shown by hydra. In fully grown Hydra, at specific part of its body there is development of bud.
This development is only during favourable period. The bud is an outgrowth developed due to repeated divisions of regenerative cells of body wall. It grows up gradually to form a small hydra. Parent hydra's dermal layers and digestive cavity are in continuity with those of the budding hydra. It receives all the nutrition from parent hydra. When the budding hydra grows sufficiently, it detaches from parent hydra. Then it leads an independent life.

In simple words: Budding in Hydra is an asexual reproductive process where a small outgrowth, or bud, develops on the parent's body during favorable conditions. This bud receives nourishment from the parent, grows into a miniature Hydra, and eventually detaches to live independently.

🎯 Exam Tip: Focus on Hydra being a multicellular organism exhibiting budding. Detail the process from bud formation to detachment, highlighting the role of regenerative cells and nourishment from the parent, and the requirement for favorable conditions.

 

Question 5. Fragmantation.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र स्पाइरोगाइरा में विखंडन (fragmentation) द्वारा अलैंगिक प्रजनन को दर्शाता है। इसमें स्पाइरोगाइरा का तंतु छोटे-छोटे टुकड़ों में टूट जाता है, और प्रत्येक टुकड़ा स्वतंत्र रूप से एक नए स्पाइरोगाइरा तंतु के रूप में विकसित होता है।
Fragmentation is one of the type of asexual reproduction in multicellular organisms. During fragmentation, the body of parent organism breaks up into many fragments. All the resulting fragments start to develop as an independent new organism. In alga Spirogyra, and sponge like Sycon asexual reproduction takes place by fragmentation. Spirogyra grow up very fast and break up into many small fragments when there are favourable conditions. Each newly formed fragment lives independently as a new Spirogyra. Similarly the body of Sycon if accidentally broken into many fragments, develops into new Sycon from each old fragment.

In simple words: Fragmentation is an asexual reproductive method where a parent organism's body breaks into multiple pieces, and each piece grows into a new, independent individual. This process is common in organisms like Spirogyra and Sycon, occurring under favorable conditions.

🎯 Exam Tip: Clearly define fragmentation as an asexual reproduction method where the parent body breaks into fragments, each developing into a new organism. Provide examples like Spirogyra and Sycon to illustrate this concept effectively.

 

Question 6. Monozygotic twins.

Answer:
The twins developed from a single embryo are called monozygotic twins. If within 8 days of zygote formation i.e. in early embryonic development cells of that embryo divide into two groups. Each one develop as two separate embryos forming two monozygotic twins. Monozygotic twins are genetically exactly similar to each other. The gender of the twins is also same.

In simple words: Monozygotic twins develop from a single fertilized egg (zygote) that splits into two embryos early in development. Because they originate from the same zygote, they are genetically identical and always of the same gender.

🎯 Exam Tip: For monozygotic twins, emphasize their origin from a single zygote, resulting in genetic identicalness and always sharing the same gender. Mentioning the timing of the split in embryonic development adds detail.

 

Read the paragraph and answer the questions given below:

Reproduction is the process by which the living species continues its existence. Lower organisms carry out asexual reproduction while higher plants and animals always show sexual reproduction. Plants reproduce asexually by methods such as fragmentation, vegetative propagation, budding, spore formation. For sexual reproduction they form gametes. In animal kingdom, budding, fission of different types and parthenogenesis are some of the methods that do not require both the sexes. Though regeneration also forms new individual, it is not considered to be a reproductive process because, basically it is a repair process. The ability to regenerate is lost in higher phyla. In human beings | it is restricted only to wound healing. Sexual reproduction is also undergoing lots of experimentation such as cloning which may make females capable of producing their own baby without intervention of any male.

Questions and Answers:

 

Question 1. How do living species continue their existence?

Answer:
Through the process of reproduction, living species continue their existence.

In simple words: Living species continue to exist by reproducing, which creates new individuals and ensures the continuation of their kind.

🎯 Exam Tip: A direct and concise answer is best for simple questions. Ensure it directly addresses "how" species continue existence.

 

Question 2. Which are asexual methods of reproduction in kingdom Animalia?

Answer:
Fission, budding and parthenogenesis are the asexual methods of reproduction in Kingdom Animalia.

In simple words: In the animal kingdom, fission, budding, and parthenogenesis are ways organisms reproduce without needing two sexes, making them asexual methods.

🎯 Exam Tip: List the specific asexual methods mentioned in the passage for animal kingdom (fission, budding, parthenogenesis). Accuracy in identifying these is key.

 

Question 3. Why is regeneration not true method of reproduction?

Answer:
Regeneration is the repair process than a reproductive process. It is not done with the intention of producing offspring, but is for healing or repairing the lost part.

In simple words: Regeneration is primarily a repair mechanism for healing wounds or regrowing lost parts, not a dedicated process for creating new offspring, which is why it's not considered a true method of reproduction in all contexts.

🎯 Exam Tip: Explain that regeneration, while it can form new individuals in some lower organisms, is fundamentally a repair process, especially in higher organisms, and not typically focused on offspring production.

 

Question 4. What are methods of reproduction in plants?

Answer:
Plants reproduce by asexual as well as sexual methods. Asexual reproduction is by fragmentation, vegetative propagation, budding, spore formation, while by formation of gametes, sexual reproduction is done.

In simple words: Plants reproduce both asexually through methods like fragmentation, vegetative propagation, budding, and spore formation, and sexually by forming gametes.

🎯 Exam Tip: For plant reproduction, state both asexual and sexual methods. List the common asexual methods specifically to provide a complete answer.

 

Question 5. What is the modern method of reproduction aimed at in higher organisms?

Answer:
Cloning is the modern method of reproduction by which production of young one can be aimed at.

In simple words: Cloning is a modern reproductive technique aimed at creating a genetically identical offspring from a single parent, bypassing traditional sexual reproduction.

🎯 Exam Tip: Identify cloning as the key modern reproductive method discussed in the context of producing offspring in higher organisms. Keep the explanation brief and direct.

 

Diagram-based Questions:

 

Question 1. Observe the figure 3.18 and answer the questions below:

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव मादा प्रजनन प्रणाली को दर्शाता है, जिसमें अंडाशय, डिंबवाहिनी (फैलोपियन ट्यूब), गर्भाशय और योनि जैसे मुख्य अंग दिखाए गए हैं, जो प्रजनन प्रक्रिया में शामिल होते हैं।
(a) What does the figure 3.18 indicate?
The figure indicates the menstrual cycle in human female.
(b) Which human organs are involved in this process?
The ovary and uterus are primarily involved in this process. But the pituitary gland also controls this cycle.
(c) Which hormones take part in this process?
Following hormones regulate this menstrual cycle.
Pituitary hormones: Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH).
Ovarian hormones: Estrogen and progesterone.
(d) What is the periodicity for these changes?
The menstrual cycle shows repetitive changes every 28 to 30 days.
(e) The body of woman undergoing this process is impure, she should remain away from other people. What is your opinion about this statement? Give justification for your opinion.
A menstruating woman is not at all with impure body. It is a natural process in which the endometrium of the uterus is sloughed off and repaired.
She should get enough rest and nutrition during this period. It is painful period in which there is a possibility of infections. Therefore, she should take ! hygienic care and rest till the bleeding persists. But blind faith and superstition to keep her away from others should not be followed.

In simple words: The diagram illustrates the human female reproductive system and related menstrual cycle. The menstrual cycle involves the ovary, uterus, and is regulated by pituitary hormones (FSH, LH) and ovarian hormones (estrogen, progesterone), occurring every 28-30 days. The belief that a menstruating woman is impure is a misconception; it's a natural bodily process requiring rest and hygiene, not isolation.

🎯 Exam Tip: When analyzing diagrams of reproductive systems, identify all key organs and their roles. For the menstrual cycle, link specific hormones to their actions and relate them to the timing of events. Address societal misconceptions with scientific facts and emphasize hygiene.

 

Question 2. Observe the diagram (Fig. 3.19) of menstrual cycle and answer the following questions:

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव मादा में मासिक धर्म चक्र को दर्शाता है, जिसमें डिंबग्रंथि और गर्भाशय में होने वाले चक्रीय परिवर्तनों के साथ-साथ हाइपोथैलेमस, पीयूष ग्रंथि और अंडाशय से स्रावित होने वाले विभिन्न हार्मोनों का प्रभाव दिखाया गया है।
(1) What is the period of menstruation?
1 to 5 days is the period of menstruation.
(2) On which day does ovulation occur during menstrual cycle?
Ovulation occurs on 14th or 15th day.
(3) During which period is corpus luteum active during menstrual cycle? Which hormones are secreted by corpus luteum ?
Corpus luteum is active till the 28th day of menstrual cycle. During this time if there is no union of sperm and ovum, then corpus luteum degenerates. Corpus luteum secretes estrogen and progesterone.
(4) In menstrual cycle which reproductive organs undergo changes?
Ovary and uterus undergo changes during menstrual cycle.
(5) Which period is said to be period of regeneration of endometrium?
In menstrual cycle, days 5 to 14 are period of regeneration of endometrium.
(6) Which period is said to be period of secretions of glands in endometrium?
Period of secretions of glands in endometrium is 15 to 28 days.

In simple words: The menstrual cycle's menstruation phase is days 1-5, with ovulation typically on days 14-15. The corpus luteum is active until day 28, secreting estrogen and progesterone, which helps regenerate the endometrium (days 5-14) and stimulates glandular secretions (days 15-28). The ovary and uterus are the main organs undergoing these cyclic changes.

🎯 Exam Tip: When answering questions about the menstrual cycle, specify the days for each phase (menstruation, ovulation, endometrium regeneration, glandular secretions) and correctly identify the hormones secreted by the corpus luteum (estrogen and progesterone).

 

Question 3. Observe the following picture and describe the type of reproduction shown in.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र प्लेनेरिया में पुनरुत्पादन की प्रक्रिया को दर्शाता है। इसमें दिखाया गया है कि यदि प्लेनेरिया को कई टुकड़ों में काट दिया जाए, तो प्रत्येक टुकड़ा अपने खोए हुए भागों को पुनर्जीवित करके एक पूर्ण नया प्लेनेरिया बना सकता है।
In developed animals like wall lizard the process of regeneration is used to restore the lost parts like tail or limbs. As the reproductive system is one of the fullfledged system in the body. the process of regeneration cannot be called type of reproduction.
But some primitive organisms such as Planaria use this method for procreation. Planaria breaks up its body into two parts. Each part has the ability to develop the lost part by process of regeneration. This forms two new Planaria.

In simple words: The picture shows regeneration in Planaria, a form of asexual reproduction where the organism's body breaks into pieces, and each piece can regrow into a complete new individual, unlike regeneration in complex animals which is primarily for repair.

🎯 Exam Tip: Clearly identify the organism (Planaria) and the specific type of reproduction (regeneration as asexual reproduction). Emphasize that while regeneration occurs in higher animals for repair, in Planaria it leads to new individuals.

 

Question 4. Answer the following questions:

Answer:
(a) "Gender of child is determined by the male partner of couple." Draw a diagram explaining the above statement.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मनुष्यों में लिंग निर्धारण की प्रक्रिया को दर्शाता है, जिसमें पिता से प्राप्त होने वाले X या Y गुणसूत्र और माता से प्राप्त होने वाले X गुणसूत्र के संयोजन के आधार पर पुत्री (XX) या पुत्र (XY) का जन्म होता है।
(b) Prepare a slogan for campaign against female foeticide.

• Save the girl child.
• Daughters give lot of joy, it is not only the boy.

(c) In the following figure, explain how new fungal colonies of mucor are formed:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र फंगस म्यूकर में बीजाणु निर्माण द्वारा अलैंगिक प्रजनन को दर्शाता है। इसमें एक तंतुमय शरीर होता है जिस पर बीजाणुधानी (sporangium) होती है, जिसके अंदर बीजाणु (spores) बनते हैं और फिर बाहर निकलकर नई कॉलोनी बनाते हैं।
Mucor is a fungus having filamentous body. The filaments bear sporangia. Mature sporangia burst and release spores. Spores germinate to form new hyphae upon getting favourable moist and warm place.
(d) Identify and state the type of reproduction represented in the above figure.
Ans. The spore formation is asexual type of reproduction seen in Mucor.

In simple words: A child's gender is determined by the male partner's sperm (carrying X or Y chromosome) fertilizing the female's egg (carrying X chromosome). Campaigns against female foeticide advocate for saving girl children, highlighting the joy they bring. In Mucor, new fungal colonies form through asexual spore formation: sporangia burst, releasing spores that germinate into new hyphae in favorable conditions.

🎯 Exam Tip: For sex determination, clearly explain the chromosomal contribution from each parent. For slogans, ensure they are impactful and socially relevant. When describing fungal reproduction, focus on the process of spore formation, release, and germination, linking it to asexual reproduction.

 

Question 5. Write the type of asexual reproduction shown in the figure.

Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र खमीर (यीस्ट) में मुकुलन (budding) द्वारा अलैंगिक प्रजनन को दर्शाता है। इसमें जनक कोशिका पर एक छोटा उभार (मुकुल) बनता है, जिसमें एक बेटी केंद्रक प्रवेश करता है और फिर यह मुकुल विकसित होकर जनक कोशिका से अलग होकर एक नई खमीर कोशिका बनाता है।
The figure shows budding in yeast. Budding is the type of asexual reproduction.

In simple words: The figure depicts budding, a type of asexual reproduction commonly observed in yeast, where a new organism develops from an outgrowth or bud due to cell division at one particular site.

🎯 Exam Tip: Identify the specific organism (yeast) and the asexual reproductive method (budding) shown in the diagram. A clear, concise identification is sufficient here.