Gametogenesis MCQ Quiz - Objective Question with Answer for Gametogenesis - Download Free PDF

The correct answer is Statement I is correct but Statement II is incorrect

Concept:

• Oogenesis is the process of formation of a mature female gamete (ovum).
• The process begins during the embryonic development stage when the stage when a couple of million gamete mother cells (oogonia) are formed within each fetal ovary; no more oogonia are formed and added after birth.
• These oogonia undergo mitotic divisions to form primary oocytes, which are arrested in the prophase stage of meiosis I until puberty.
• Graafian follicles are the mature ovarian follicles that release the ovum during ovulation.

Explanation:

• Statement I: Oogenesis is initiated during the embryonic development stage. This statement is correct because the formation of primary oocytes happens during fetal development, and these oocytes remain arrested in prophase I until puberty.
• Statement II: A large number of Graafian follicles degenerate during the phase from birth to puberty. This statement is incorrect because Graafian follicles are mature follicles that appear after puberty. A large number of primary follicles degenerate during the phase from birth to puberty. Therefore, at puberty only 60,000-80,000 primary follicles are left in each ovary.

The correct answer is Oogonia

Concept:

• Gametogenesis is the process by which gametes (sperm and eggs) are produced in the reproductive organs. In males, this process is called spermatogenesis, and in females, it is called oogenesis.
• During gametogenesis, cells undergo several stages of division and development, starting from diploid stem cells and ending with haploid gametes.
• A diploid cell contains two sets of chromosomes (2n), one set inherited from each parent, while a haploid cell contains only one set of chromosomes (n).

Fig: Spermatogenesis and Oogenesis

Explanation:

• Oogonia: These are the diploid stem cells in the ovaries that undergo mitosis to produce primary oocytes. Since oogonia are in the early stage of oogenesis and have not yet undergone meiosis, they are diploid (2n).
• Secondary Oocyte: This is the haploid cell that results from the first meiotic division of a primary oocyte. It is ready to undergo the second meiotic division, which is completed only if fertilization occurs. Therefore, secondary oocytes are haploid (n).
• Secondary Spermatocytes: These are the haploid cells produced by the first meiotic division of primary spermatocytes during spermatogenesis. They undergo the second meiotic division to produce spermatids. Hence, secondary spermatocytes are haploid (n).
• Spermatozoa: These are the mature male gametes produced by the differentiation of spermatids. Spermatozoa are haploid (n) and are involved in fertilization to form a diploid zygote.

The correct answer is 1,20,000-1,60,000

Explanation:

• Primary follicles are the initial stage of the ovarian follicles that women are born with. These follicles undergo various developmental stages, leading to the release of a mature egg during ovulation.
• At birth, a female has about 1 to 2 million primary follicles in her ovaries. However, this number decreases significantly by the time she reaches puberty.
• A large number of these follicles degenerate during the phase from birth to puberty.
• Therefore, at puberty only 60,000-80,000 primary follicles are left in each ovary.
• Therefore, in both ovaries 1,20,000-1,60,000 primary follicles are left.

The correct answer is A - Endometrium- Undergoes cyclical changes, B - Myometrium - Thick layer of smooth muscle and C - Perimetrium - Thin membranous

Explanation:

• The uterus is a female reproductive organ that is part of the reproductive system. It has three layers: the perimetrium, myometrium, and endometrium.
• The external thin membranous perimetrium, middle thick layer of smooth muscle, myometrium and inner glandular layer called endometrium that
  lines the uterine cavity.
• The endometrium undergoes cyclical changes during menstrual cycle while the myometrium exhibits strong contraction during delivery of the baby.
• The myometrium is the middle layer of the uterine wall, consisting of thick smooth muscle tissue that is essential for uterine contractions during labor.
• The perimetrium is the outermost layer of the uterus, consisting of a thin membranous tissue that provides a smooth covering to the uterus.

Fig: Female Reproductive System

The correct answer is b, c, d

Concept:

• The mammary gland is a complex structure located in the thoracic region and is responsible for milk production in females. It consists of various components including lobes, ducts, and supportive tissues.
• A sectional view of the mammary gland region of the thorax includes several key anatomical structures such as the mammary ducts, ampulla, pectoralis major muscle, ribs, nipple, areola, and lactiferous ducts.

Fig: Sectional view of mammary glands

Explanation:

• Ampulla + Mammary duct: These are parts of the milk duct system where milk is stored and transported. The ampulla is an expanded region of the duct where milk accumulates before being expelled.
• Pectoralis Major + Rib + Nipple: The pectoralis major is a major muscle of the chest, the ribs provide structural support, and the nipple is the external part of the mammary gland where milk is secreted.
• Areola + Lactiferous duct: The areola is the pigmented area surrounding the nipple, and the lactiferous ducts are channels that carry milk from the mammary glands to the nipple.

Other Options:

• Mammary lobe + Isthmus: While the mammary lobe is part of the glandular tissue, the term 'isthmus' is not typically used in the context of mammary anatomy. This makes the option partly incorrect.

Concept:

• Spermatogenesis is the process by which sperm are produced in the testis in males.
• In the testis, at puberty sperms are produced from the immature germ cells called spermatogonia.
• Spermatogenesis takes place under the influence of the hypothalamic hormone - Gonadotropin Releasing Hormone (GnRH).
• Sperms (spermatozoa) thus produced are the microscopic haploid male gametes. During the process of fertilization, the union of male and female gametes gives rise to a diploid zygote.
• A sperm is a slender, motile and flagellated structure that is about 60µ in length.
• A sperm comprises a head, a middle piece and a tail.​

​

Important Points

• Head -
  • ​The haploid nucleus of sperm is present in the sperm head.
  • The nucleus comprises a vacuole.
  • The anterior portion of the nucleus is covered by a cap-like structure called the acrosome.
  • The acrosome covers the anterior two-thirds of the nucleus.
  • The acrosome is filled with an enzyme that helps in the fertilization of the ovum.
• Midpiece -
  • ​The middle region of the sperm comprises of compact helical mass of mitochondria.
  • The mitochondria provide energy for the movement of the tail.
  • This in turn facilitates sperm motility which is essential for fertilization.
  • Thus the middle piece of the sperm in Human Reproduction helps to produce energy for sperm motility.
• ​Tail - 
  • ​The sperm tail facilitates the movement of the sperm cell by moving in a whip-like manner.
• ​A plasma membrane envelops the whole body of the sperm.
• The plasma membrane helps protect the sperm against extracellular injuries.

Additional Information

• ​The Sertoli cells are present in the seminiferous tubules of the testis.
• They provide nourishment to the developing sperm and are hence also known as nurse cells.

So the correct answer is option 3 (to produce energy for sperm motility).

Key Points

• Reproduction is the biological process of producing genetically similar offspring to the parent organism.
• Both male and female reproductive systems are composed of different types of parts.
• The male reproductive system includes a pair of testes, accessory ducts, glands, and the external genitalia.
• The female reproductive system includes a pair of ovaries along with a pair of oviducts, uterus, cervix, vagina, and external genitalia located in the pelvic region.

Explanation:

• Option 1 - Matched
  • Each testicular lobule contains one to three highly coiled seminiferous tubules in which sperms are produced.
  • These seminiferous tubules are lined on the inside by two types of cells namely male germ cells and Sertoli cells.
  • Sertoli cells provide nutrition to the germ cells.
  • Sertoli cells are also known as nurse cells as they nourish the spermatozoa.
• Option 2 - Matched​
  •  The Graafian follicle is the fluid-filled structure that surrounds and shields the oocyte in the mammal's ovary.
  • The tertiary follicle undergoes further changes to form the Graafian follicle.
  • During ovulation Graafian follicle ruptures to release the secondary oocyte from the ovary.
  • After ovulation, the empty Graafian follicle changes into a yellow body called the corpus luteum.
  • The Corpus luteum acts as an endocrine gland and secretes progesterone.
  • Progesterone helps in the implantation.
• Option 3 - Mismatched
  • A collection of radially elongated follicle cells is present outside the ovum's zona pellucida layer, known as corona radiata.
  • The cells of corona radiata are adhered to each other by hyaluronic acid.
  • While sperm is the male gamete and does not contain these layers.

• Option 4 - Matched
  • Leydig cells are also called Interstitial cells, located outside the seminiferous tubules.
  • Leydig cells synthesize and secrete testosterone.
  • Testosterone helps in spermatogenesis and regulates the functions of male accessory sex organs such as seminal vesicles, prostate glands, urethra, etc.

Hence, the correct option is (3) Corona radiata - sperm.

The correct answer is Secondary spermatocytes have 23 chromosomes and undergo second meiotic division

Concept:

• Spermatogenesis is the process of the production of sperms from the immature male germ cells in testis.
• This process begins at puberty due to a significant increase in the secretion of gonadotropin-releasing hormone (GnRH). 
• Spermatogenesis occurs within the seminiferous tubules in each testis.
• Both mitosis and meiosis are involved in this process.
• Spermatogonia are present on the inner wall of the seminiferous tubules and multiply by mitotic division.
• Each spermatogonium is diploid and contains 46 chromosomes.
• Some spermatogonia become primary spermatocyte and periodically undergo meiotic division.
• The primary spermatocyte completes the first meiosis and forms two equal haploid secondary spermatocytes.
• The secondary spermatocytes undergo the second meiotic division and produce four equal haploid spermatids.
• Spermatids are transformed into spermatozoa by the process termed spermiogenesis.
• Sperms are haploid and contain 23 chromosomes.
• Sequence of cell stages during spermatogenesis is: Spermatogonia → Spermatocytes  →  Spermatids  → Spermatozoa.

​

Explanation:

Option  1)  Spermatogonia have 46 chromosomes and always undergo meiotic cell division- INCORRECT

• They undergo mitotic division.
• So, this is an incorrect option

Option  2)  Primary spermatocytes divide by mitotic cell division- INCORRECT

• Primary spermatocytes divide by meiotic division I.
• So, this is an incorrect option

Option  3)  Secondary spermatocytes have 23 chromosomes and undergo second meiotic division- CORRECT

• This is a correct option as after the first meiotic division it becomes 23 chromosomes and undergoes the second meiotic division.

Option 4)  Spermatozoa are transformed into spermatids INCORRECT

• From spermatids it becomes spermatozoa.
• So, this is an incorrect option

So, the correct option is Option  3.

Concept:

• Spermatogenesis is the process of the production of sperms from the immature male germ cells in testis.
• This process begins at puberty due to significant increase in the secretion of gonadotropin releasing hormone (GnRH). 
• Spermatogenesis occurs within the seminiferous tubules in each testis.
• Both mitosis and meiosis are involved in this process.

Important Points

• Spermatogonia, present on the inner wall of the seminiferous tubules, multiply by mitotic division.
• Each spermatogonium is diploid(2n) and contains 46 chromosomes.
• Some spermatogonia differentiate into primary spermatocyte and periodically undergo meiotic division.
• The primary spermatocyte completes the first meiosis and forms two equal haploid(n) secondary spermatocytes.
• The secondary spermatocytes undergo the second meiotic division to produce four equal haploid(n) spermatid.
• Spermatids are transformed into spermatozoa by the process called spermiogenesis.
• Thus, spermatozoa are also haploid(n) and contains 23 chromosomes.

Therefore, the correct sequence is:

• (D) Spermatogonia
• (E) Primary spermatocytes
• (A) Secondary Spermatocyte
• (B) Spermatid 
• (C) Spermatozoa

Hence, the correct answer is option 4.

The correct answer is option 3.

Concept: 

• Meiosis I known as a reductional division reduces the number of chromosomes in primary oocytes and primary spermatocytes.
• Then, it leads to the formation of secondary oocytes and secondary spermatocytes.

​​Explanation:

• Spermatogenesis takes place in the seminiferous tubule of the testes.
• The spermatogonia are the germ cells for synthesizing sperm.
• It matures and undergoes mitosis division to produce primary spermatocytes.
• Primary spermatocytes undergo meiosis I to form secondary spermatocytes.
• Secondary spermatocytes further undergo an equational division (mitotic division) to form four equal haploid spermatids. The process by which spermatids transform into spermatozoa (sperms) is termed spermiogenesis. I
• Secondary spermatocyte undergoes meiosis II to form spermatids.

Oogenesis

•  In the female reproductive system, oogenesis is the process in which the primary egg cell develops into a mature ovum. The diploid egg cell increases in size and transforms into a primary oocyte.
• The secondary oocyte is produced by the reductional division or meiosis I of the primary oocyte. It has 23 chromosomes.

Therefore, the correct answer is option 3.

Concept:

• Spermatogenesis is the process by which sperm are produced in the testis in males.
• In the testis, at puberty sperms are produced from the immature germ cells called spermatogonia.
• Spermatogenesis takes place under the influence of the hypothalamic hormone - Gonadotropin Releasing Hormone (GnRH).
• Sperms (spermatozoa) thus produced are the microscopic haploid male gametes. During the process of fertilization, the union of male and female gametes gives rise to a diploid zygote.
• A sperm is a slender, motile and flagellated structure that is about 60µ in length.
• A sperm comprises a head, a middle piece and a tail.​

​

Important Points

• Head -
  • ​The haploid nucleus of sperm is present in the sperm head.
  • The nucleus comprises a vacuole.
  • The anterior portion of the nucleus is covered by a cap-like structure called the acrosome.
  • The acrosome covers the anterior two-thirds of the nucleus.
  • The acrosome is filled with an enzyme that helps in the fertilization of the ovum.
• Midpiece -
  • ​The middle region of the sperm comprises of compact helical mass of mitochondria.
  • The mitochondria provide energy for the movement of the tail.
  • This in turn facilitates sperm motility which is essential for fertilization.
  • Thus the middle piece of the sperm in Human Reproduction helps to produce energy for sperm motility.
• ​Tail - 
  • ​The sperm tail facilitates the movement of the sperm cell by moving in a whip-like manner.
• ​A plasma membrane envelops the whole body of the sperm.
• The plasma membrane helps protect the sperm against extracellular injuries.

Additional Information

• ​The Sertoli cells are present in the seminiferous tubules of the testis.
• They provide nourishment to the developing sperm and are hence also known as nurse cells.

So the correct answer is option 3 (to produce energy for sperm motility).

Key Points

• Reproduction is the biological process of producing genetically similar offspring to the parent organism.
• Both male and female reproductive systems are composed of different types of parts.
• The male reproductive system includes a pair of testes, accessory ducts, glands, and the external genitalia.
• The female reproductive system includes a pair of ovaries along with a pair of oviducts, uterus, cervix, vagina, and external genitalia located in the pelvic region.

Explanation:

• Option 1 - Matched
  • Each testicular lobule contains one to three highly coiled seminiferous tubules in which sperms are produced.
  • These seminiferous tubules are lined on the inside by two types of cells namely male germ cells and Sertoli cells.
  • Sertoli cells provide nutrition to the germ cells.
  • Sertoli cells are also known as nurse cells as they nourish the spermatozoa.
• Option 2 - Matched​
  •  The Graafian follicle is the fluid-filled structure that surrounds and shields the oocyte in the mammal's ovary.
  • The tertiary follicle undergoes further changes to form the Graafian follicle.
  • During ovulation Graafian follicle ruptures to release the secondary oocyte from the ovary.
  • After ovulation, the empty Graafian follicle changes into a yellow body called the corpus luteum.
  • The Corpus luteum acts as an endocrine gland and secretes progesterone.
  • Progesterone helps in the implantation.
• Option 3 - Mismatched
  • A collection of radially elongated follicle cells is present outside the ovum's zona pellucida layer, known as corona radiata.
  • The cells of corona radiata are adhered to each other by hyaluronic acid.
  • While sperm is the male gamete and does not contain these layers.

• Option 4 - Matched
  • Leydig cells are also called Interstitial cells, located outside the seminiferous tubules.
  • Leydig cells synthesize and secrete testosterone.
  • Testosterone helps in spermatogenesis and regulates the functions of male accessory sex organs such as seminal vesicles, prostate glands, urethra, etc.

Hence, the correct option is (3) Corona radiata - sperm.

Key Points

• The ovum is the female gamete or the sex cell.
• It has a haploid set of chromosomes.
• The ovum is released from the ovaries, the primary female reproductive organ.
• Ova are produced by both animals and terrestrial plants.
• An ovum is generally a spherical, non-motile gamete, and its cytoplasm is full of yolk.
• It fuses with the male gamete (sperm) to form a zygote.

Explanation:

• The life span of an ovum is 24 hours.
• If the ovum does not get fertilized by the sperm within 24 hours, the ovum starts to degenerate.
• When it is fertilized, it undergoes a series of cell division.

Hence, the correct option is (3) 24 hours. 

The correct answer is Secondary spermatocytes have 23 chromosomes and undergo second meiotic division

Concept:

• Spermatogenesis is the process of the production of sperms from the immature male germ cells in testis.
• This process begins at puberty due to a significant increase in the secretion of gonadotropin-releasing hormone (GnRH). 
• Spermatogenesis occurs within the seminiferous tubules in each testis.
• Both mitosis and meiosis are involved in this process.
• Spermatogonia are present on the inner wall of the seminiferous tubules and multiply by mitotic division.
• Each spermatogonium is diploid and contains 46 chromosomes.
• Some spermatogonia become primary spermatocyte and periodically undergo meiotic division.
• The primary spermatocyte completes the first meiosis and forms two equal haploid secondary spermatocytes.
• The secondary spermatocytes undergo the second meiotic division and produce four equal haploid spermatids.
• Spermatids are transformed into spermatozoa by the process termed spermiogenesis.
• Sperms are haploid and contain 23 chromosomes.
• Sequence of cell stages during spermatogenesis is: Spermatogonia → Spermatocytes  →  Spermatids  → Spermatozoa.

​

Explanation:

Option  1)  Spermatogonia have 46 chromosomes and always undergo meiotic cell division- INCORRECT

• They undergo mitotic division.
• So, this is an incorrect option

Option  2)  Primary spermatocytes divide by mitotic cell division- INCORRECT

• Primary spermatocytes divide by meiotic division I.
• So, this is an incorrect option

Option  3)  Secondary spermatocytes have 23 chromosomes and undergo second meiotic division- CORRECT

• This is a correct option as after the first meiotic division it becomes 23 chromosomes and undergoes the second meiotic division.

Option 4)  Spermatozoa are transformed into spermatids INCORRECT

• From spermatids it becomes spermatozoa.
• So, this is an incorrect option

So, the correct option is Option  3.

The correct answer is 1,20,000-1,60,000

Explanation:

• Primary follicles are the initial stage of the ovarian follicles that women are born with. These follicles undergo various developmental stages, leading to the release of a mature egg during ovulation.
• At birth, a female has about 1 to 2 million primary follicles in her ovaries. However, this number decreases significantly by the time she reaches puberty.
• A large number of these follicles degenerate during the phase from birth to puberty.
• Therefore, at puberty only 60,000-80,000 primary follicles are left in each ovary.
• Therefore, in both ovaries 1,20,000-1,60,000 primary follicles are left.