Students get through the TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction which is useful for their exam preparation.

TN State Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Very short answer questions

Question 1.
Define Gametogenesis.
Answer:
Gametogenesis is defined as a process, through which the formation of male and female gametes are produced.

Question 2.
Name two reproductive hormones secreted by the pituitary gland.
Answer:

  1. Follicle Stimulating Hormone (FSH).
  2. Luteinizing Hormone (LH).

Question 3.
Define organogenesis.
Answer:
Organogenesis is a series of events through which the formation of specific tissues, organs, and organ systems from three germ layers takes place.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 4.
What are Sertoli cells? Explain its functions.
Answer:
Sertoli cells are one of the two types of cells of the seminiferous tubule. It provides nourishment to the sperm till maturation. It also secretes a hormone namely inhibin, which is involved in the negative feedback control of sperm production.

Question 5.
Leydig cells are endocrine in nature. Justify.
Answer:
Leydig cells are endocrine in nature because they secrete a hormone, androgens namely testosterone, which initiates the process of spermatogenesis.

Question 6.
Name the accessory ducts associated with the male reproductive system.
Answer:

  1. Rete testis.
  2. Vasa efferentia.
  3. Epididymis.
  4. Vas deferens.

Question 7.
Explain the function of the seminal vesicle.
Answer:
Seminal vesicles secrete an alkaline fluid, containing fructose sugar, ascorbic acid, prostaglandins. It also secretes a coagulating enzyme called vesiculate, which helps in sperm motility.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 8.
Mention the female accessory reproductive organs.
Answer:

  1. Fallopian tube.
  2. Uterus.
  3. Vagina.

Question 9.
What are the three layers of the uterus wall?
Answer:
The wall of the uterus has three layers of tissue namely the perimetrium, myometrium, and endometrium.

Question 10.
Explain the functions of the skene’s gland.
Answer:
The skene’s glands are present on the anterior wall of the vagina, surrounding the lower end of the urethra. These glands secrete a lubricating fluid.

Question 11.
Define spermiogenesis.
Answer:
Spermiogenesis is a process in which a spermatid is transformed into spermatozoa or sperms.

Question 12.
Explain the term mitochondrial spiral.
Answer:
Mitochondrial spiral is the spirally twisted mitochondria around the axial filament of the middle piece of sperm.

Question 13.
What are the phases of the menstrual cycle?
Answer:

  1. Menstrual phase
  2. Follicular phase
  3. Ovulatory phase
  4. Luteal or secretory phase.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 14.
Explain briefly about LH surge.
Answer:
In the middle of the ovulatory phase, maximum secretion of LH, known as LH surge takes place. This in term induces the rupture of the Graafian follicle, resulting in the release of the ovum from the ovary wall into the peritoneal cavity.

Question 15.
What is meant by menopause?
Answer:
Menopause is a phase, in which ovulation and menstruation stop in a woman’s life.

Question 16.
Explain the morula stage.
Answer:
The morula stage of the human embryo in which a loose collection of cells into a berry-shaped cluster of 16 or more cells is formed after 72 hours of fertilization.

Question 17.
Define monozygotic twins.
Answer:
When a single fertilized egg splits into two during the first cleavage, each daughter egg develops into each individual forming identical twins.

Question 18.
Define parturition.
Answer:
Parturition is the completion stage of pregnancy and childbirth.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 19.
What is colostrum?
Answer:
Colostrum is a yellow fluid secreted by the mammary gland during the initial few days after parturition.

Question 20.
Expand the following abbreviations:
Answer:
(i) WABA,
(ii) WHO,
(i) WABA: World Alliance for Breastfeeding Action.
(ii) WHO: World Health Organisation.

Short answer questions

Question 1.
What is the constitution of the seminiferous tubule?
Answer:
The seminiferous tubule is made up of two types of stratified epithelium namely Sertoli cells or nurse cells and spermatogenic cells or male germ cells. Sertoli cells are elongated and pyramidal cells, which nourish the growing sperm. They also secrete a hormone namely inhibin, which is responsible for the negative feedback control of sperm production. Spermatogenic cells form the spermatozoa by meiosis or reduction division.

Question 2.
Distinguish between Sertoli cells and Leydig cells.
Answer:

Sertoli cells Leydig cells
Sertoli cells are elongated and pyramidal cells. Embedded in soft connective tissue surrounding the seminiferous tubule.
They provide nourishment to the sperms till maturation. They are endocrine in nature.
They secrete a hormone called inhibin, which is responsible for the negative feedback control of sperm production. They secrete androgens, namely the testosterone which is responsible for the initiation of the process of spermatogenesis.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 3.
Write down the functions of the accessory glands of the male reproductive system.
Answer:
The accessory glands of the male reproductive system are:

  1. Seminal vesicle.
  2. Bulbourethral gland or Cowper’s gland.
  3. Prostate gland.

Seminal vesicles:
secrete seminal plasma having fructose sugar, ascorbic acid, prostaglandins, and a coagulating enzyme, namely vesiculase, which helps sperm motility. The seminal plasma is alkaline in nature.
Bulbourethral glands: They secrete a lubricating fluid and helps in the lubrication of the penis.
Prostate gland: It secretes a slightly acidic fluid containing citrate, several enzymes, and prostate-specific antigens.

Question 4.
Explain the structure of the penis.
Answer:
The penis is a male copulatory organ, made up of special tissues which facilitate the erection of the penis to deliver the seminal fluid in the vagina of the female. The enlarged end of the penis is called the glans penis. It is covered by a loose fold of skin called foreskin or prepuce. The structure of the penis facilitates insemination.

Question 5.
Describe the structure of Uterus.
Answer:
The Uterus is otherwise called a womb, which is an inverted pear-shaped structure. It is a hollow thick-walled and highly vascularized structure lying between the urinary bladder and the rectum in the pelvic cavity. The body of the uterus occupies the major portion and the fundus is the rounded region superior to it.
Cervix is the narrow opening of the uterus into the vagina. The external orifice and internal orifice through which the cervical canal opens communicates with the vagina and with the uterus respectively. The birth canal is formed by the cervical canal and vagina.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 6.
Distinguish between Bartholin’s glands and skene’s glands.
Answer:

Bartholin’s glands Skene’s glands
These glands are located posterior to the left and right of the opening of vagina. These glands are seen on the anterior wall of the vagina and the lower end of the urethra.
They secrete lubricating mucus and are homologous to the bulbourethral glands of the males. They also secrete a lubricating fluid and are homologous to the prostate gland of males.

Question 7.
Explain briefly the normal development of the breast.
Answer:
The normal development of breasts in females takes place at puberty and progresses with changes in each menstrual cycle. The breast size is mainly due to fat deposits. The glandular structure is underdeveloped in a non-pregnant women. In pregnant women, the glandular structure develops. The efficiency of lactation does not have any influence on the size of the breast.

Question 8.
Name the important hormones involved in spermatogenesis.
Answer:

  1. Gonadotropin-Releasing Hormone (GnRH).
  2. Follicle Stimulating Hormone (FSH).
  3. Luteinizing Hormone (LH).

Question 9.
Write down the events in the follicular phase of the menstrual cycle.
Answer:
The follicular phase of the menstrual cycle extends from the 5th day of the cycle until the time of ovulation. During this phase, a fully mature Graafian follicle is formed from the primary follicle in the ovary. Simultaneously, the endometrium regenerates through proliferation. The secretion of FSH and LH during this phase induces these changes in the ovary and uterus. The follicular cells secrete oestrogen during this phase.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 10.
What is meant by implantation?
Answer:
The fertilized egg undergoes cleavage and forms a fluid-filled hollow ball of about 100 cells, called the blastocyst. Under the influence of progesterone, the embryo moves through the fallopian tube into the uterine cavity and becomes embedded in the endometrium of the uterus and this process is called implantation.

Question 11.
Name the hormones secreted by the placenta during pregnancy.
Answer:

  1. Human Chorionic Gonadotropin (HCG).
  2. Human Chorionic Somatomammotropin (HCS) or Human Placental Lactogen (HPL).
  3. Oestrogens and Progesterone.

Question 12.
What is meant by Polycystic Ovary Syndrome (PCOS).
Answer:
PCOS is a complex endocrine disorder. This affects women in their reproductive phase of the year.
This is mainly due to the formation of many partially formed follicles which contain an egg each. These eggs do not grow to maturity and take part in fertilization. The symptoms of this syndrome include irregular menstrual cycles, increased androgen levels, excessive facial and body hair growth, acne, obesity, reduced fertility, and increased risk of diabetes.

Long answer questions

Question 1.
Write about the accessory glands of the male reproductive system.
Answer:
The accessory glands associated with the male reproductive system include the following:
(a) A paired seminal vesicles.
(b) Bulbourethral glands or Cowper’s glands.
(c) A single prostate gland.

  1. Seminal vesicles: Seminal vesicles are located on either side of the prostate gland and secrete an alkaline fluid called seminal plasma, which contains fructose sugar, ascorbic acid, prostaglandins, and a coagulating enzyme called vesiculates, which helps sperm motility.
  2. The Bulbourethral glands: These glands are located inferior to the prostate gland and they secrete a lubricating fluid, which helps to lubricate the penis.
  3. The prostate glands: The single prostate gland is placed just below the urinary bladder, encircling the urethra. It secretes slightly acidic fluid, which contains citrate, several enzymes and prostate-specific antigens.
    The secretions of the three glands along with sperm is called semen or seminal fluid.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 2.
Draw the diagrammatic view of the female reproductive system and label the parts.
Answer:
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 1

Question 3.
Give an account of mammary glands.
Answer:
Mammary glands are modified sweat glands present in both sexes. It is functional in females and rudimentary in males. In humans, a pair of mammary glands is placed in the thoracic region. The glandular tissues and variable quantities of fat are present in mammary glands along with a median nipple. The nipple is surrounded by a pigmented area called the areola. The areolar glands, modified sebaceous glands are present on the surface. They help in reducing the cracking of the skin of the nipple.
Each mammary gland consists of 2 – 25 lobes. They are separated by fat and connective tissues. Each lobe contains many lobules, which contain acini or alveoli lined by epithelial cells. Milk is secreted by the cells of alveoli, which opens into mammary tubules. The mammary duct is formed by joining the tubules of each lobe. The mammary ampulla is formed by joining several mammary ducts. The mammary duct is connected to the lactiferous duct in the nipple. The lactiferous sinus is the expansion of the lactiferous duct under the nipple and serves as a reservoir of milk. On the surface of the nipple, each lactiferous duct opens by a minute pore.

Question 4.
Explain the sequence of events in the fertilization process in humans.
Answer:
Fertilization is a process in which a haploid male gamete fuses with a haploid ovum to form a diploid zygote.
The sperms are deposited in the female reproductive tract by copulation and sperms undergo a process called capacitation. It is a biochemical event that enables the sperm to penetrate through the egg membrane and fertilize the egg.
Fertilization of the ovum takes place only if the ovum and sperm are deposited simultaneously to the ampullary isthmic junction of the fallopian tube.
The sperm has to penetrate the multiple layers of granulosa, which are around the ovum forming corona radiata. The follicular cells are held together by hyaluronic acid, an adhesive substance. The acrosome of the sperm secretes a proteolytic enzyme, hyaluronidase, which lysis the membrane and helps the penetration of sperm through corona radiata and zona pellucida. The process is called acrosomal reaction. Once fertilization is over, a barrier membrane, the fertilization membrane around the ovum is formed by the cortical granules from the cytoplasm of the ovum. This membrane prevents further entry of other sperms. Thus polyspermy is prevented.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Choose the correct answers.

Question 1.
Match the following:
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 2
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iv); (q)-(iii); (r)-(i); (s)-(ii)
(c) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
(d) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
Answer:
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)

Question 2.
Match the following:
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 3
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
(c) (p)-(ii); (q)-(iii); (r)-(iv); (s)-(i)
(d) (p)-(iv); (q)-(iii); (r)-(i); (s)-(ii)
Answer:
(c) (p)-(ii); (q)-(iii); (r)-(iv); (s)-(i)

Question 3.
Match the following:
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 4
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
(c) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
(d) (p)-(iii); (q)-(i); (r)-(iv); (s)-(ii)
Answer:
(b) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 4.
Match the following:
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 5
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
(c) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
(d) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
Answer:
(d) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)

Question 5.
Match the following:
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 6
(a) (p)-(iv); (q)-(iii); (r)-(ii); (s)-(i)
(b) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)
(c) (p)-(iii); (q)-(iv); (r)-(i); (s)-(ii)
(d) (p)-(iii); (q)-(i); (r)-(iv); (s)-(ii)
Answer:
(b) (p)-(ii); (q)-(i); (r)-(iv); (s)-(iii)

Question 6.
The fusion of male and female gametes is called as:
(a) Oogenesis
(b) Fertilization
(c) Gastrulation
(d) Spermiation
Answer:
(b) Fertilization

Question 7.
The hormone inhibin is secreted by:
(a) Pituitary
(b) Leydig cells
(c) Sertoli cells
(d) Endometrium
Answer:
(c) Sertoli cells

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 8.
The bulbourethral gland is otherwise called as:
(a) Prostate gland
(b) Seminal vesicle
(c) Cowper’s gland
(d) Skene’s gland
Answer:
(c) Cowper’s gland

Question 9.
The mammary glands are modified:
(a) Sebaceous glands
(b) Green glands
(c) Sweat glands
(d) Bartholin’s gland
Answer:
(c) Sweat glands

Question 10.
The acrosomal membrane disintegrates by the proteolytic enzyme called:
(a) Leutinising hormone
(b) Hyaluronidase
(c) Lactogenase
(d) Prolactin
Answer:
(b) Hyaluronidase

Question 11.
Choose the odd man out:
(a) human Chorionic Gonadotropin
(b) Follicle Stimulating Hormone.
(c) human Chorionic Somatomammotropin
(d) human Placental Lactogen.
Answer:
(b) Follicle Stimulating Hormone.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

Question 12.
Choose the odd one.
(a) Seminal vesicle
(b) Prostate gland
(c) Cowper’s gland
(d) Bartholin’s gland
Answer:
(d) Bartholin’s gland

Question 13.
Indicate the odd one.
(a) Gametogenesis
(b) Spermiogenesis
(c) Spermatogenesis
(d) Oogenesis
Answer:
(b) Spermiogenesis

Question 14.
Choose the odd man out.
(a) Hyaluronidase
(b) FSH – Follicle Stimulating Hormone
(c) LH – Lutenizing Hormone
(d) ABP – Androgen Binding Protein
Answer:
(a) Hyaluronidase

15. Find out the odd one.
(a) Labia majora
(b) Labia minora
(c) Zona pellucida
(d) Hymen
Answer:
(c) Zona pellucida

16. Choose the correct pair.
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 7
Answer:
(b)

17. Which of the following pair is wrong?
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 8
Answer:
(c)

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

18. Choose the correct pair.
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 9
Answer:
(d)

19. Choose the incorrect pair.
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 10
Answer:
(a)

20. Which of the following is the correct pair?
TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction 11
Answer:
(b)

21. Assertion: Leydig cells surrounding the seminiferous tubules are endocrine in nature.
Reason: They secrete testosterone hormone which initiates the process of spermatogenesis.
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true, Reason is not the correct explanation of Assertion.
(c) Assertion is true, Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

22. Assertion: The seminal vesicles secrete a slightly acidic fluid called seminal plasma.
Reason: Seminal plasma helps in the movement of the sperm.
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true, Reason is not the correct explanation of Assertion.
(c) A is true, Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(d) Both Assertion and Reason are false.

23. Assertion: The medulla of the ovarian stroma is a loose connective tissue with abundant blood vessels, lymphatic vessels and nerve fibres.
Reason: in the medulla, the various stages of ovarian follicles are present.
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true, Reason is not the correct explanation of Assertion.
(c) Assertion is true, Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(c) Assertion is true, Reason is false.

24. Assertion: Acrosome is a small cup-like pointed structure at the tip of the nucleus of sperm, which helps the sperm to penetrate the ovum during fertilization.
Reason: Acrosome contains a proteolytic enzyme, hyaluronidase popularly known as sperm lysin which helps to penetrate the ovum during fertilization.
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true, Reason is not the correct explanation of Assertion.
(c) Assertion is true, Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.

25. Assertion: During the luteal phase of the menstrual cycle, the Graafian follicle is transformed into a transitory endocrine gland called the corpus luteum.
Reason: Corpus luteum secretes a large amount of Oestrogen, which is essential for the maintenance of the endometrium.
(a) Assertion and Reason are true, Reason is the correct explanation of Assertion.
(b) Assertion and Reason are true, Reason is not the correct explanation of Assertion.
(c) Assertion is true, Reason is false.
(d) Both Assertion and Reason are false.
Answer:
(c) Assertion is true, Reason is false.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

26. Which of the following a correct statement?
(a) At the end of gametogenesis in females, each primary Oocyte gives rise to only one haploid ovum.
(b) At the end of gametogenesis in females, each primary Oocytes gives rise to four haploid ovum.
(c) At the end of gametogenesis in females, each primary Oocyte gives rise to three polar bodies and two ovum.
(d) None of the above.
Answer:
(a) At the end of gametogenesis in females, each primary Oocyte gives rise to only one haploid ovum.

27. Choose the incorrect statement:
(a) Human ovum is non-cleidoic in nature.
(b) Human ovum is alecithal in nature.
(c) Human ovum contains a small nucleus in the cytoplasm.
(d) Human ovum is microscopic in nature.
Answer:
(c) Human ovum contains a small nucleus in the cytoplasm.

28. Indicate the correct statement:
(a) The Acrosome of sperm possess nebenkem.
(b) The middle piece of sperm contain a mitochondrial spiral.
(c) The proximal centriole of sperm gives rise to the axial filament.
(d) None of the above.
Answer:
(b) The middle piece of sperm contain a mitochondrial spiral.

TN Board 12th Bio Zoology Important Questions Chapter 2 Human Reproduction

29. Choose the incorrect statement:
(a) Inhibin is a hormone involved in the negative feedback control of sperm production.
(b) Leydig cells are endocrine in nature.
(c) Vesiculase enzyme is a proteolytic enzyme.
(d) Corpus luteum secretes lot of progesterone.
Answer:
(c) Vesiculase enzyme is a proteolytic enzyme.

30. Which of the following is a correct statement?
(a) Mammary glands are modified sebaceous glands.
(b) It is functional in males and rudimentary in females.
(c) Mammary glands are modified sweat gland.
(d) None of the above.
Answer:
(c) Mammary glands are modified sweat gland.