Class 10 NCERT Solutions How do Organisms Reproduce

Class 10 NCERT Solutions How do Organisms Reproduce- NCERT Solutions prepared for CBSE students by the best teachers in Delhi.

Class X Chapter 8 – How do Organisms Reproduce Science

Question 1: What is the importance of DNA copying in reproduction?

Answer: DNA (Deoxyribonucleic acid) is the genetic material found in the chromosomes, which are present in the nucleus of a cell. The DNA is the information site for making proteinsand each specific type of protein leads to a specific type of body design. Thus, it is the DNA molecule that determines the body design of an individual. Therefore, it can be concluded that it is the DNA that gets transferred from parents to offsprings and makes them look similar. DNA determines body structure

Question 2: Why is variation beneficial to the species but not necessarily for the individual?

Answer: Variations are beneficial to the species than individual because sometimes for a species, the environmental conditions change so drastically that their survival becomes difficult. For example, if the temperature of water increases suddenly, then most of the bacteria living in that water would die. Only few variants that are resistant to heat would be able to survive. However, if these variants were not there, then the entire species of bacteria  would have been destroyed. Thus, these variants help in the survival of the species.However, all variations are not necessarily beneficial for the individual organisms.

Class X Chapter 8 – How do Organisms Reproduce Science

Question 1: How does binary fission differ from multiple fission?

Answer: In binary fission, a single cell divides into two equal halves. Amoeba and Bacteria divide by binary fission. Binary fission in Amoeba

In multiple fission, a single cell divides into many daughter cells simultaneously. Amoeba and Plasmodium divide by multiple fission. Multiple fission in Plasmodium

Question 2: How will an organism be benefited if it reproduces through spores?

Answer: There are many advantages, if an organism reproduces through spores. Advantages of spore formation:

· Large numbers of spores are produced in one sporangium.

· Spores are distributed easily by air to far-off places to avoid competition at one place.

· Spores are covered by thick walls to prevent dehydration under unfavourable conditions.

Question 3: Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

Answer:Simple organisms such as Hydra and Planaria are capable of producing new individuals through the process of regeneration. The process of regeneration involves the formation of new organisms from its body parts. Simple organisms can utilize this method of reproduction as their entire body is made of similar kind of cells in which any part of their body can be formed by growth and development. However, complex organisms have organ-system level of organization. All the organsystems of their body work together as an interconnected unit. They can regenerate their lost body parts such as skin, muscles, blood, etc. However, they cannot give rise to new individuals through regeneration.

Question 4: Which of the following is a plant hormone?

  (a) Insulin

  (b) Thyroxin

 (c) Oestrogen

 (d) Cytokinin

Answer: (d) Cytokinin is a plant hormone.

Question 5: Why is DNA copying an essential part of the process of reproduction?

Answer: DNA (Deoxyribonucleic acid) copying is an essential part of reproduction as it passes genetic information from parents to offspring. It determines the body design of an individual. The reproducing cells produce a copy of their DNA through some chemical reactions and result in two copies of DNA. The copying of DNA always takes place along with the creation of additional cellular structure. This process is then followed by division of a cell to form two cells.

Class X Chapter 8 – How do Organisms Reproduce Science

Question 1: How is the process of pollination different from fertilization?

Answer: Pollination is the process of transfer of pollens from anther to stigma. It occurs with the help of certain pollinators such as air, water, birds, or some insects. Fertilization, on the other hand, is the fusion of the male and female gametes. It occurs inside the ovule and leads to the formation of zygote.

Question 2: What is the role of the seminal vesicles and the prostate gland?

Answer: The secretions from seminal vesicles and prostate glands lubricate the sperms and provide a fluid medium for easy transport of sperms. Their secretion also provides nutrient in the form of fructose, calcium, and some enzymes.

Question 3: What are the changes seen in girls at the time of puberty?

Answer:Secondary sexual characteristics in girls:

· Increase in breast size and darkening of skin of the nipples present at the tips of the breasts.

· Appearance of hair in the genital area.

· Appearance of hair in other areas of skin like underarms, face, hands, and legs.

· Increase in the size of uterus and ovary.

· Beginning of menstrual cycle.

· More secretion of oil from the skin, which results in the appearance of pimples.

Question 4: How does the embryo get nourishment inside the mother’s body?

Answer: The embryo develops inside the mother’s body for about nine months. Inside the uterus, the outer tissue surrounding the embryo develops finger-like projections called villi. These villi are surrounded by uterine tissue and maternal blood. They provide a large surface area for exchange of oxygen and nutrients. Also, there is a special tissue calledplacenta, which is embedded in the uterine wall. The embryo receives the oxygen and nutrients from the mother’s blood via the placenta. The waste materials produced by the embryo are also removed through the placenta.

Question 5: If a woman is using a copper−T, will it help in protecting her from sexually transmitted diseases?

Answer: No. Using a copper-T will not provide a protection from sexually transmitted diseases, as it does not prevent the entry of semen. It only prevents the implantation of the embryo in the uterus.


Students should free download the NCERT solutions and get better marks in exams. Studiestoday.com panel of teachers recommend students to practice questions in NCERT books and download NCERT solutions.

Tags: 

 


Click to View or Download pdf file
Click for more Science Study Material

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

CBSE Class 12 Evaluation Criteria 2021

SUMMARY OF THE POLICY FOR TABULATION OF MARKS FOR CLASS XII BOARD EXAMINATIONS 2021   1(a) Due to cancellation of the Board examinations, the assessment of theory portion of 80/70/60/50/30 marks will be done by the school based on the following:     Class...

Time management for CBSE students

The first thing to learn about Time Management is that time is theoretical so you can’t really manage it. What you do when you get into time management, is that you manage yourself. You decide what has to be done, when it must be done and how to do it in the stipulated...

CBSE Assessment Framework

The Central Board of Secondary Education (CBSE) today, announced a suggested competency-based assessment framework to strengthen India’s existing school education system for secondary level (classes 6-10) and improve the overall learning outcomes of students across...

CBSE asks schools to load Class 12 Internal Assessment Marks

This has a reference to the letter no CBSE/COORD/2021 dated 11.02.2021 regarding conduct of the School-Based Assessment (Internal Assessment/Practical/ Project) of Class-XII and uploading the marks by 11.06.2021. It has been observed that some schools have not been...

FAQs on Policy for Tabulation of Marks for Class 10 Board Exams

ON POLICY Question.1 How CBSE will declare the result of Class-X? Answer. Results of Class X Board will be declared on the basis of an objective criterion developed by the Board vide Notification no.CBSE/CE/2021 dated 01.05.2021. Question.2. If any candidate is not...

×
Studies Today