NEET Biology Human Reproduction MCQs Set 41

Answer: (b) golgi bodies

Explanation:
1. Acrosome of sperm is formed from Golgi bodies and contains hydrolysing enzymes for sperm penetration.
2. Hence option (b) is correct: golgi bodies

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (b) ovum

Explanation:
1. Cumulus covers the ovum.
2. The ovum at the matured conditions has a massy cloud formed with a flat base and rounded outlines piled up like a mountain.
3. Hence option (b) is correct: ovum

Teacher's Note:
1. A granulosa cell is a somatic cell found closely associated with the developing female gamete (oocyte or egg) in the ovary of mammals.
2. Granulosa cells form a single flattened layer around the oocyte in the primordial ovarian follicle and later in follicle development they advance to form a multi layered cumulus surrounding the oocyte.

Answer: (a) menopause

Explanation:
1. Menopause is the period when ovulation and menstrual cycle stop in human females.
2. The period of menopause is between 45-55 years.
3. Hence option (a) is correct: menopause

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (d) under developed limbs

Explanation:
1. Woman who took the drug thalidomide in early pregnancy gave birth to children with severe birth defects such as missing or shortened limbs.
2. Hence option (d) is correct: under developed limbs

Teacher's Note:
1. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (c) mitochondria and 9 + 2 arrangement of microtubules.

Explanation:
1. A cross section at the midpoint of the middle piece of human sperm will show mitochondria and 9+2 arrangement of microtubules.
2. Hence option (c) is correct: mitochondria and 9 + 2 arrangement of microtubules.

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (b) Endometrium regenerates : 5-10 days

Explanation:
1. The proliferative phase lasts for about 14 days in which the endometrium becomes thicker by rapid cell multiplication. 1 2 3 4 5 6 7 8 9 10 Cycle begins here Menstrual Phase 11 12 28 Proliferative Phase 13 27 Secretory Phase 14 15 16 17 18 19 20 21 22 23 24 25 26 Corpus luteum degenerates Ovulation.
2. Hence option (b) is correct: Endometrium regenerates : 5-10 days

Teacher's Note:
1. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (b) Hyalurodinase: For penetrating egg membrane

Explanation:
1. Sperm is the male gamete that fuses with female gamete and produce a diploid cell called zygote.
2. During fertilization, acrosome of the sperm releases some enzymes, particularly hyaluronidase, that facilitates the penetration of the sperm into ovum.
3. Hence option (b) is correct: Hyalurodinase: For penetrating egg membrane

Teacher's Note:
1. These enzymes dissolve the membrane enveloping the ovum and help the sperm head to enter the ovum.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (d) 4:1

Explanation:
1. Four viable sperm cells are produced from one primary sex cell, whereby only one viable egg cell is produced, due to the unequal division of cytoplasm and the formation of polar bodies, which wither and die.
2. Hence option (d) is correct: 4:1

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (b) ovary

Explanation:
1. Corpus luteum is a yellow coloured mass of cells found in ovary.
2. Corpus luteum secretes progesterone hormone, which is essential for maintaining pregnancy and therefore also called as “pregnancy hormone.”.
3. Hence option (b) is correct: ovary

Teacher's Note:
1. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (b) Testes of rabbit

Explanation:
1. Leydig cells are the characteristic of mammalian testis.
2. They produce hormone, testosterone meant for developement of secondary sexual characters in males.
3. Hence option (b) is correct: Testes of rabbit

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (c) Incomplete

Explanation:
1. Zygote divides partially in meroblastic cleavage.
2. Hence option (c) is correct: Incomplete

Teacher's Note:
1. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (b) the cyclic release of pituitary gonadotropins and ovarian steroids is continued.

Explanation:
1. The high levels of estrogen and progesterone in the maternal circulation during pregnancy inhibit the cyclic release of pituitary gonadotropins and prevent the menstrual cycles.
2. Pregnancy hormones include hCG, which maintains the corpus luteum of pregnancy and forms the basis for pregnancy diagnosis urine tests.
3. Hence option (b) is correct: the cyclic release of pituitary gonadotropins and ovarian steroids is continued.

Teacher's Note:
1. Ovarian and placental estrogen and progesterone, human placental lactogen, and pituitary prolactin stimulate development of the ducts and alveoli in the mammary glands.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (c) 60, 40

Explanation:
1. Ejaculation of human male contains about 200 – 300 million sperms, of which for normal fertility 60 % sperms must have normal shape and size and at least 40 % must show energetic motility.
2. Hence option (c) is correct: 60, 40

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (c) characterized by a yellow colour

Explanation:
1. Corpus luteum is a yellow endocrine body in the ovary.
2. Macula lutea is the yellow spot of the retina.
3. So the common feature is their yellow colour.
4. Hence option (c) is correct: characterized by a yellow colour

Teacher's Note:
1. Corpus luteum is the fluid filled yellow body in the ovary and macula lutea is the yellow spot present in the eyes.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (b) In the second cleavage division, one of the two blastomeres usually divides a little sooner than the second.

Explanation:
1. In mammals the first cleavage is meridional and the second is also meridional, but one of the two blastomeres divides slightly earlier than the other.
2. Cleavage does not increase the total mass of protoplasm, and the blastomeres become smaller with each division.
3. The solid ball of cells is the morula, not a hollow ball.
4. Hence option (b) is correct: In the second cleavage division, one of the two blastomeres usually divides a little sooner than the second.

Teacher's Note:
1. Repeated cleavage in the zygote brings about the distribution of the cytoplasm of the zygote among blastomere and increases mobility of the protoplasm which facilitates morphogenetic movements for cell differentiation.
2. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. In female, Graafian follicle forms corpus luteum after ovulation.
2. The cells of corpus luteum are called luteal cells.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. The cytoplasm of luteal cells have yellow granules called lutein which secrete the hormone progesterone to maintain pregnancy if fertilization takes place.
2. In the absence of fertilization, corpus luteum degenerates and forms corpus albicans and there is decrease in progesterone level as well.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. Hyaluronidase, a hydrolytic enzyme is an acrosomal content in mammalian sperm.
2. It helps at the time of fertilization during the penetration of the sperm into the ovum.
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. Based on the amount of yolk mammalian eggs are alecithal means egg without yolk.
2. Microlecithal eggs contain very little yolk e.g., sea urchin, starfish.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. The acrosome is at the tip of the sperm head and the mitochondrial spiral lies in the middle piece, so the Assertion is false.
2. The acrosome does not contain mitochondria, so the Reason is false too.
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. Head of a sperm has acrosome but the spiral row of mitochondria are present in the mid (connecting) piece of the sperm.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Males have more stature than females because of the action of male sex hormone- testosterone which is secreted by testis in males.
2. Body starts secreting testosterone from the age of puberty.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Its secretion is under the influence of Luteinizing Hormone (LH) of the anterior lobe of pituitary gland.
2. Testosterone controls the development of secondary sexual characters in males like hoarseness of voice, development of facial hairs, bone growth, calcium retention, closing of epiphysial cartilage.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Testicular lobules are compartments of the testis that contain seminiferous tubules, so the Assertion is true.
2. Fertilisation happens in the female tract (ampulla of the fallopian tube), so lobules are not involved in it and the Reason is false.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Testicular lobules are the compartments present in the testes, are not involved in the process of fertilization as whole.
2. Fusion of male and female gametes is called fertilization.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Leydig cells, also known as interstitial cells, are found adjacent to the seminiferous tubules in the testicle.
2. They produce testosterone in the presence of luteinizing hormone (LH).
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Human reproduction questions are mostly NCERT based: learn the gland, hormone and structure for each function.
2. Draw the menstrual cycle with hormone levels to answer sequence questions quickly.