RBSE Solutions Class 12 Biology Chapter 28 Man-Reproductive System

RBSE Class 12 Biology Chapter 28 Multiple Choice Questions

 

Question 1. Graafian follicles are found in:
(a) Thyroid gland of a man
(b) A prostate gland of a man
(c) Ovaries of woman
(d) Testes of man
Answer: (c) Ovaries of woman
In simple words: Graafian follicles are special small sacs found inside the ovaries of women, where eggs grow and mature before release.

🎯 Exam Tip: Remember that Graafian follicles are a key structure in the female reproductive system and are directly involved in egg development and ovulation.

 

Question 2. Which gland secretes an alkaline fluid that helps in smoothening of the vagina at the time of mating?
(a) Prostate
Answer: The Cowper's glands, also known as bulbo-urethral glands, secrete an alkaline fluid. This fluid helps to lubricate and smoothen the vagina at the time of mating, and its alkaline nature helps neutralize any acidic environment. The fluid helps prepare the reproductive tract.
In simple words: Cowper's glands make a slippery, basic fluid that helps to prepare the vagina for mating by lubricating it.

🎯 Exam Tip: Focus on the specific gland name (Cowper's or bulbo-urethral) and the two main properties of its secretion: alkaline nature and lubricating function for easy reference.

 

Question 3. After how many days menstrual cycle occurs in the women.
(a) 14 days
(b) 20 days
(c) 32 days
(d) 28 days
Answer: (d) 28 days
In simple words: A woman's menstrual cycle usually lasts about 28 days, which is roughly a month.

🎯 Exam Tip: The 28-day cycle is an average; be aware that individual cycles can vary slightly in length, but 28 days is the typical duration.

RBSE Class 12 Biology Chapter 28 Very Short Answer Type Questions

 

Question 1. Write the function of Corpus luteum.
Answer: The corpus luteum is a temporary endocrine gland that forms in the ovary after ovulation. It primarily secretes two important hormones: progesterone and relaxin. Progesterone is crucial for maintaining the uterine lining for a potential pregnancy.
In simple words: The corpus luteum makes hormones called progesterone and relaxin, which are important for maintaining pregnancy.

🎯 Exam Tip: Remember that the corpus luteum is vital for both maintaining the uterine lining and relaxing pelvic ligaments, especially during pregnancy.

 

Question 2. Which of the cells function as endocrine gland in the testes? Write the name of the hormone secreted by these cells.
Answer: Leydig's cells, also known as interstitial cells, function as the endocrine gland within the testes. These specialized cells secrete the androgen hormone, primarily testosterone. Testosterone plays a vital role in male reproductive health.
In simple words: Leydig's cells in the testes act like a gland and make the androgen hormone, also known as testosterone.

🎯 Exam Tip: Associate Leydig's cells directly with androgen production and their crucial endocrine role in the testes for male sexual development.

 

Question 3. Write the name and function of the hormone secreted by Leydig's cells.
Answer: Leydig's cells secrete the androgen hormone. This hormone is responsible for controlling spermatogenesis (the process of sperm production) and developing male secondary sexual characteristics, such as facial hair, a deeper voice, and increased muscle mass. It plays a central role in male puberty.
In simple words: Leydig's cells make androgen hormone, which helps make sperm and gives men their male features.

🎯 Exam Tip: When asked about Leydig's cells, always highlight both functions: sperm production (spermatogenesis) and the development of secondary sexual traits.

 

Question 4. Write the names of primary sex organs found in male and female human beings.
Answer: The primary sex organs in male human beings are the testes. In female human beings, the primary sex organs are the ovaries. These organs are responsible for producing gametes (sperm and egg) and sex hormones.
In simple words: For males, testes are the main sex organs. For females, ovaries are the main sex organs because they make reproductive cells.

🎯 Exam Tip: Remember that primary sex organs are defined by their role in producing gametes and sex hormones, which are crucial for reproduction.

 

Question 6. Write two secondary sexual characters of a woman.
Answer: Two prominent secondary sexual characters of a woman include well-developed mammary glands (breasts) and a high-pitched voice. These physical changes typically appear during puberty and signify sexual maturity.
In simple words: Women develop breasts and have a high-pitched voice as part of their secondary sexual traits.

🎯 Exam Tip: Secondary sexual characters are physical features that distinguish the sexes but are not directly involved in reproduction; they often develop during puberty.

RBSE Class 12 Biology Chapter 28 Short Answer Type Questions

 

Question 1. What are the changes visible at the puberty in male and female human beings?
Answer: Changes in Male and Female at Puberty:

In simple words: During puberty, boys develop deeper voices, facial hair, and their reproductive organs grow. Girls develop breasts, their voices get higher, and they start their menstrual cycles.

🎯 Exam Tip: When describing puberty changes, categorize them clearly by sex and focus on both physical development and the maturation of reproductive functions.

 

Question 2. During the winter season, the scrotal sac shrinks and become small. Explain it.
Answer: Spermatogenesis, the process of sperm production, requires a slightly cooler temperature of about 34 to 35°C, which is 2 to 4°C lower than the normal body temperature. In winter, as the outside temperature drops, the scrotal sacs shrink and move closer to the body. This action helps to keep the testes warm enough to maintain the optimal temperature needed for proper sperm formation. The cremaster muscle helps in this movement.
In simple words: Sperm need a cooler temperature than the body. In winter, the scrotum pulls close to the body to keep the testes warm enough for sperm production.

🎯 Exam Tip: The key concept here is that testes are kept outside the body to maintain an optimal, slightly lower temperature for successful spermatogenesis.

 

Question 3. What is Cryptorchidism?
Answer: Cryptorchidism is a medical condition where one or both testes fail to descend into the scrotal sac during fetal development or shortly after birth. This leads to the arrest of spermatogenesis because the higher temperature inside the abdominal cavity prevents proper sperm formation. This condition often requires medical intervention.
In simple words: Cryptorchidism happens when the testes do not move down into the scrotum. This stops sperm from being made because the body is too warm for it.

🎯 Exam Tip: Emphasize that cryptorchidism is a developmental issue resulting in non-functional testes due to the adverse effects of higher body temperature.

 

Question 4. What is andropause?
Answer: Andropause, often referred to as male menopause, is a natural process characterized by a gradual decrease in the secretion of testosterone hormone. It typically occurs in men normally after the age of 60 years. This hormonal change can lead to various physical, emotional, and sexual symptoms.
In simple words: Andropause is like menopause for men, where testosterone levels slowly drop, usually after age 60.

🎯 Exam Tip: Compare andropause to menopause to help recall its meaning, focusing on the decline in male hormones and its association with aging.

 

Question 5. What do you mean by Sertoli cells? What are their functions?
Answer: Sertoli cells are specialized cells found inside the seminiferous tubules of the testes. Their primary functions are to provide structural support and nourishment to the developing sperms, aiding in their maturation. They also form the blood-testis barrier, protecting germ cells from harmful substances. Sertoli cells also secrete inhibin and androgen-binding protein.
In simple words: Sertoli cells are inside the testes. They feed and support the growing sperm and protect them from harm.

🎯 Exam Tip: Remember Sertoli cells as "nurse cells" that are crucial for sperm development, protection, and maturation within the testes.

 

Question 6. Draw a neat diagram of mammary glands of a woman and explain how it is helpful in reproductive activity.
Answer: Mammary glands, commonly known as breasts, are accessory reproductive organs in females that begin to develop significantly at puberty. They are composed of connective tissues, 15-20 tubular partitioned lobules, and fatty tissue. The nipple, surrounded by a darker area called the areola mammae, has multiple pores for milk ejection. The growth and function of these glands are regulated by several hormones, including somatotropin, prolactin, estrogen, progesterone, and oxytocin. In reproductive activity, specifically after childbirth, the mammary glands produce milk to feed the infant. Mother's milk is a complete food, providing essential nutrients and helping to develop immunity in the child through immunoglobulins.
In simple words: Mammary glands are breasts that grow at puberty. After a baby is born, they produce milk to feed the baby, giving it nutrients and helping its immune system.

🎯 Exam Tip: Focus on the structure (lobules, fatty tissue, nipple, areola) and the function (lactation and immunity for the newborn), noting the hormonal control during pregnancy and lactation.

 

Question 7. Draw labelled diagram of a transverse section of the testis.
Answer:
In simple words: This diagram shows a cross-section of a mammalian testis. You can see the internal structures like the seminiferous tubules where sperm develop, and other cells like Leydig cells and Sertoli cells that support this process.

🎯 Exam Tip: Practice drawing and labeling key structures such as seminiferous tubules, Leydig cells, and Sertoli cells, as they are fundamental to understanding testicular anatomy and function.

RBSE Class 12 Biology Chapter 28 Essay Type Questions

 

Question 1. Describe the male reproductive system of a man with suitable diagram.
Answer: The male reproductive system includes a pair of testes, which are oval-shaped organs suspended outside the body in a muscular sac called the scrotum. The wall of the testes is covered by an elastic layer of thin, hairy skin and a thick inner subcutaneous layer of unstriated muscle fibers known as the Dartos muscle. Each half of the scrotal sac contains rod-shaped striated muscle fibers called the Cremaster muscle, which connects the subcutaneous layer to the abdominal subcutaneous muscle. The scrotal cavity connects to the abdominal cavity via a white inguinal canal. In adult mammals, the testes are ex-abdominal, meaning they are located outside the abdominal cavity in the scrotal sacs. This external location is crucial because spermatogenesis (sperm production) requires a slightly lower temperature (33-35°C) than the core body temperature (2-4°C less). The testis descends into the scrotal sac through an inguinal canal, accompanied by the testicular artery, vein, and nerve, which together form the spermatic cord. Each testis is also attached within the scrotal sac by a gubernaculum, both of which contain elastin fibers. If the testes fail to descend into the scrotal sacs, the higher abdominal temperature arrests spermatogenesis, a condition known as cryptorchidism.
In simple words: The male reproductive system has testes in a sac called the scrotum outside the body. This is because sperm need a cooler temperature to grow. Hormones and special muscles help the testes stay in the right place.

🎯 Exam Tip: Remember the importance of the scrotal location for temperature regulation, the main components (testes, epididymis, vas deferens, seminal vesicles, prostate, bulbourethral glands), and their functions in sperm production and delivery.

 

Question 2. Explain the structure of ovary.
Answer: Structure of Ovary: Ovaries are a pair of almond-shaped structures found within the abdominal cavity of a woman. Each ovary is typically 1.5-3 cm long and 8 mm thick. They are located behind the kidneys in the pelvic region, connected by ligaments. The primary functions of the ovary are to produce ova (eggs) through oogenesis and to secrete important female hormones, primarily estrogen and progesterone, which regulate the menstrual cycle and support pregnancy. These hormones are essential for the development of secondary sexual characteristics.
In simple words: Ovaries are small, almond-shaped organs in a woman's lower belly. They make eggs and female hormones like estrogen and progesterone.

🎯 Exam Tip: Key points for the ovary structure and function include its location, characteristic shape, its role in producing eggs (ova), and the critical secretion of female hormones.

 

Question 3. Explain the role of various accessory glands in male and female helping in the reproduction process.
Answer: Accessory glands play a vital role in supporting the reproduction process by producing fluids that nourish and transport gametes.
(1) Accessory Glands in Male: Three types of accessory glands are found in men, which secrete their fluids into the urethra. These secretions are essential for the viability and motility of spermatozoa. The combined secretions from accessory glands, epididymis, and sperm collectively form semen.

• Prostate Glands: The prostate gland secretes an alkaline fluid that neutralizes the acidic environment of the vagina, which is beneficial for sperm survival. This fluid contains important components like phosphatase, citrate, lysozyme, and fibrinolysin. Its secretions help activate the sperms and prevent the semen from coagulating too quickly. In older men, an enlarged prostate can cause problems with urine discharge. The prostate gland usually consists of four lobes: one ventral, one dorsal, and two lateral.
• Seminal Vesicles: Often referred to as uterus masculine, there is a pair of seminal vesicles in men. The secretions from the seminal vesicles constitute about 70% of the total seminal fluid. This fluid is alkaline, slimy, and has a pH of approximately 7.4. It contains essential substances such as fructose (for sperm energy), ascorbic acid, prostaglandins, and various enzymes.
• Cowper's Glands (Bulbo-urethral glands): These are small, round, yellowish glands found in pairs, opening into the middle part of the urethra. They secrete a transparent, alkaline fluid with a pH ranging from 7.5 to 8. This fluid helps to make the urethra alkaline before copulation, clearing any residual acidic urine.

(2) Various Accessory Glands in Female: There are two main types of sex accessory glands in females:

• Prostate Glands (Paraurethral Glands): A pair of glands located in the anterior part of the vagina that secrete fluids. Their secretions help keep the vagina moist before copulation, aiding in lubrication.
• Bartholin Glands: Situated on both sides of the vaginal opening, these are bean-shaped glands. They secrete an alkaline and lubricating fluid, which keeps the vulva moist and facilitates sexual intercourse.

In simple words: Male accessory glands like the prostate, seminal vesicles, and Cowper's glands produce fluids that help sperm survive and move. Female accessory glands like the "prostate glands" (paraurethral) and Bartholin's glands keep the vagina moist for mating.

🎯 Exam Tip: When discussing accessory glands, clearly distinguish between male and female systems, noting their specific secretions and their roles in sperm viability, lubrication, and overall reproductive success.

 

Question 4. Write short notes on:
1. Ovary
2. Penis
3. Epididymis
4. Secondary sexual characters
5. Corpus luteum
Answer:
1. Ovary: Ovaries are paired, almond-shaped structures found in the abdominal cavity. Each ovary typically measures 1.5-3 cm in length and 8 mm in thickness. They are positioned behind the kidneys in the pelvic region. The ovaries are responsible for producing ova (eggs) and secreting crucial female hormones like estrogen and progesterone, which regulate the menstrual cycle.
2. Penis: In men, the penis is a cylindrical, erectile, and highly vascularized copulatory organ, suspended between the legs alongside the scrotal sacs. Its body consists of three blood sinuses (two dorsolateral corpora cavernosa and one ventral corpus spongiosum) made of filamentous, muscular connective tissues. The apex, called the glans penis, is a swollen part and is covered by a cap-like fold of skin known as the prepuce. During erection, blood fills these sinuses, making the penis hard and swollen for deep penetration into the vagina, enabling semen ejaculation. Normally, these sinuses are empty, allowing only urine to flow through the urinogenital aperture.
3. Epididymis: The epididymis is a thin, highly coiled, comma-shaped tube, approximately 6 meters long, that leads into the vas deferens. Its coiled rings are adhered by connective tissues. The outer side is covered with a thick muscular layer, and the inner side is lined with stratified epithelium. It is attached to the inner surface of the testis and has three parts: the caput (globulus major), corpus, and cauda (globulus minor). The globulus major receives the vasa efferentia, while the globulus minor opens into the vas deferens. The epididymis stores sperm and is the primary site for their physiological maturation.
4. Secondary sexual characters: Secondary sexual characters are physical traits that emerge during puberty and differentiate males from females, but are not directly involved in reproduction.

5. Corpus luteum: The corpus luteum forms from the follicular cells of the burst follicle after ovulation, under the control of luteinizing hormone (LH). It contains yellow-colored luteal cells with lutein pigments. This structure functions as a temporary endocrine gland, secreting progesterone and inhibin hormones, which are vital for maintaining the uterine lining for pregnancy. A blood clot at its center is known as corpus haemorrhagicum. If fertilization does not occur, the corpus luteum degenerates into a non-functional, colorless corpus albicans.
In simple words:

• Ovary: Makes eggs and female hormones.
• Penis: Male organ for mating and urine release, becomes erect to deliver sperm.
• Epididymis: Stores sperm and helps them mature after they are made in the testes.
• Secondary sexual characters: Body features that differ between men and women, like voice pitch or hair, which show up at puberty but are not directly for making babies.
• Corpus luteum: A temporary gland in the ovary that makes hormones after an egg is released, very important for supporting a possible pregnancy.

🎯 Exam Tip: For short notes, define the structure or concept clearly, state its location, and list its key functions or characteristics concisely, focusing on distinguishing features.

 

Question 5. Explain with diagram the female reproductive system.
Answer: The female reproductive system consists of primary and accessory reproductive organs, working together to enable reproduction. The primary reproductive organs are a pair of ovaries. Accessory reproductive organs found in a female include the oviducts (Fallopian tubes), uterus, vagina, and vulva. Additionally, reproductive glands and mammary glands are also considered accessory organs.

(1) Ovary: Ovaries are a pair of almond-shaped structures located within the abdominal cavity of a woman. Each ovary is typically 1.5-3 cm long and 8 mm thick. They are found behind the kidneys in the pelvic region. Their main role is to produce ova (eggs) and secrete essential female hormones, such as estrogen and progesterone.
(2) Histology of Ovary: A pair of ovaries is attached dorsally in the abdominal cavity with the help of a mesovarium, which originates from the visceral peritoneum. The ovary has germinal epithelium inside the mesovarium, composed of cuboidal germ cells. The ovary's stroma is made of fibrous connective tissues; its peripheral part is condensed (cortex), and the inner less dense part is the medulla. The cortical part of the ovary contains various ovarian follicles:

• Primary follicles: These are formed during the embryonic stage and begin to grow at puberty. Each contains an oogonium surrounded by a layer of follicular cells.
• Secondary follicles: These have a primary oocyte surrounded by two layers of follicular cells.
• Tertiary follicles: These contain a primary oocyte surrounded by three layers of follicular cells.
• Mature follicles or Graafian follicles: These are fully developed follicles. The stalk, known as the germ hill or cumulus oophoritis, supports the oocyte. The Graafian follicle gradually migrates to the periphery and protrudes. The mature follicle bursts at the surface, releasing the secondary oocyte, a process called ovulation.
• Atretic follicle: Sometimes, a Graafian follicle fails to ovulate and degenerates gradually. This degenerating follicle is called an atretic follicle, and the process is known as atresia. This can occur due to vitamin E deficiency or hormonal imbalance.
• Corpus luteum: After ovulation, the follicular cells of the burst follicle reorganize under the control of luteinizing hormone (LH) to form the corpus luteum. It contains yellow-colored luteal cells with lutein pigments. This structure performs an endocrine function, secreting progesterone and inhibin hormones, essential for maintaining pregnancy. There is a blood clot in the center of the corpus luteum, called corpus haemorrhagicum.
• Corpus Albicans: If no fertilization occurs, the corpus luteum begins to degenerate, forming a non-functional, colorless corpus albicans.

3. Oviduct: There is a pair of oviducts, also known as Fallopian tubes, which originate from the Mullerian duct. The anterior end of the oviduct is modified to form a ciliated, fimbriated funnel called the infundibulum. Its mouth is funnel-shaped and referred to as the ostium. The ovum (egg) enters the oviduct through this oviducal funnel. The middle part of the oviduct is specifically called the Fallopian tube. Its wall has unstriated muscles and is internally ciliated. The Fallopian tube is the crucial site for secondary maturation division, fertilization, and the initial stages of embryonic development.
4. Uterus: The posterior part of the oviduct modifies to form the uterus. The uterus in women is simplex (single). A uterine wall typically has three distinct layers:

• Epimedium: This is the outermost layer of the uterus, made up of visceral peritoneum.
• Myometrium: This is the middle layer, which is composed of strong smooth muscles. It contains the longest smooth muscle fibers, making it highly contractile, especially during childbirth.
• Endometrium: This is the innermost layer of the uterus. It undergoes cyclical changes during the menstrual cycle and is where the embryo implants and develops.

In simple words: The female reproductive system includes ovaries, which make eggs and hormones, and tubes (oviducts) where eggs travel and fertilization can happen. The uterus is where a baby grows, and the vagina is the birth canal. All these parts work together for reproduction.

🎯 Exam Tip: For a comprehensive explanation, describe each main organ (ovary, oviduct, uterus, vagina) with its structure, histology (where applicable), and function. Include the hormonal control and cyclical changes, highlighting the pathway of the egg.

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