31 Years NEET Previous Year Questions: Human Reproduction - 1 Free MCQ

• Menarche is the first occurrence of menstruation in a female, marking the onset of reproductive capability.
• Menopause is the permanent cessation of menstruation at the end of the reproductive period.
• Ovulation is the release of an egg from the ovary.
• Diapause is a delayed developmental phase seen in some animals, not related to menstruation.

A. Correct – By the end of 12 weeks (first trimester), all major organ systems are formed and start functioning.|
B. Incorrect – While organ formation begins earlier, full development of organ systems completes around 12 weeks, not 8.
C. Correct – The heart develops and begins to beat by the end of the first month.
D. Correct – Limbs and digits form by the end of the second month (8 weeks).
E. Correct – Fine hair called lanugo appears around the fifth month of gestation.

A. True
In females, meiosis (reductive division) begins during fetal life (in the form of primary oocytes).
In males, meiosis starts at puberty.
B. True
In males, meiosis I and II occur rapidly in succession.
In females, meiosis I completes at ovulation (after years of arrest), and meiosis II completes only after fertilization—hence, a much longer gap.
C. False
The first polar body is formed after the completion of meiosis I, which occurs from the primary oocyte, not during its formation.
D. False
The LH surge triggers ovulation, not menstrual bleeding.
Menstruation occurs due to drop in progesterone and estrogen when the corpus luteum degenerates.

The Fallopian tubes, also known as oviducts or uterine tubes, are structures in the female reproductive system that stretch from the uterus to the ovaries. These tubes play a crucial role in the journey of the egg from the ovary to the uterus. The primary components of the Fallopian tubes include the infundibulum, ampulla, and isthmus:
When examining the options provided, Option A mentions the "Uterine fundus". The fundus is actually the top part of the uterus, situated above the openings of the Fallopian tubes into the uterine cavity. The fundus of the uterus is not a part of the Fallopian tubes; instead, it is a region of the uterus itself. Therefore, the correct answer is: Option A: Uterine fundus

To answer this question correctly, we need to evaluate the facts around each statement individually before making a comparison:

• Statement I: The presence or absence of hymen is not a reliable indicator of virginity. This statement is true. The hymen is a thin, elastic membrane located at the entrance to the vagina. Contrary to common belief, the hymen is not an impermeable barrier that is always torn when virginity is lost via sexual intercourse. It can vary greatly in shape and size from person to person. Some girls are born without a hymen, some have small hymenal tissue, and others have hymens that are very elastic. Moreover, the hymen can be stretched or torn during a variety of non-sexual activities such as tampon use, physical exercise (e.g., biking, gymnastics), or medical examinations. Therefore, the state of the hymen is not a definite indicator of virginity, making statement I true.
• Statement II: The hymen is torn during the first coitus only. This statement is false. As previously mentioned, the hymen can be stretched or torn by activities that are not sexual in nature. Additionally, many women may not experience tearing of the hymen at all during their first sexual intercourse. In cases where the hymen is more elastic or resilient, it may not tear during sexual activity. Furthermore, there are practices and surgeries, such as hymenoplasty, that can restore or create a hymen-like structure, indicating that the hymen can be altered multiple times throughout a woman's life. Thus, the claim that the hymen is torn only during the first coitus is incorrect.

Based on the explanations provided:
Option C (Statement I is true but Statement II is false) is the correct answer.

The correct answer is option no. (A) as

(A) is FSH which is a pituitary hormone.
(B) is Leydig cells which are found in the interstitial space outside of the seminiferous tubules.
(C) is Sertoli cells are found inside the seminiferous tubules.
(D) is Spermiogenesis which is a process that helps in transformation of spermatids into spermatozoa.

Option (a) is the correct answer to this question because statement I and statement II both are correct. Vas deferens receives a duct from seminal vesicle and opens into urethra as the ejaculatory duct. The cavity of cervix is called cervical canal which along with vagina forms the birth canal.

The correct answer is option (d) as first menstrual cycle that begins at puberty is called menarche.
Cyclic menstruation is an indicator of normal reproductive phase and extends between menarche and menopause.
In primates, cyclical changes during reproduction are called menstrual cycle.

Option (b) is the correct answer because both Assertion and Reason are true.
Implantation is embedding of the blastocyst into endometrium of uterus.
Correct explanation of reason is Corpus luteum secretes large amount of progesterone which is essential for maintenance of endometrium of uterus. In absence of fertilisation, the corpus luteum degenerates hence the decrease in the level of progesterone hormone will cause disintegration of endometrium leading to menstruation.

Statement I: The release of sperm into the seminiferous tubules is called spermiation; this is correct. After the development of spermatids into sperms, the sperms are released from the seminiferous tubules by the process of spermiation

Statement II: Spermiogenesis is the process of formation of sperms from spermatogonia; this is incorrect. Spermiogenesis is the process by which spermatids develop into sperms. 

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Oogenesis starts at embryonic development stage in females. 

Concept:

• The process of formation of the male gamete (sperm) is called spermatogenesis.
• The process of formation of the female gamete (ovum) is called oogenesis.

Explanation:

Let us see some similarities and differences between oogenesis and spermatogenesis:

So, the correct answer is option D.

Sperm plasma membrane receptors bind to ZP3 on the zona pellucida. Binding to ZP3 allows sperm to adhere to the zona pellucida, which is an important step in fertilisation.

The secretions of the acrosome help the sperm enter into the cytoplasm of the ovum through the zona pellucida and the plasma membrane.

Fig: Sperm binding receptors

Relaxin is produced first by the corpus luteum of the ovary and later by the placenta. It helps in parturition as it increases the flexibility of the pubic symphysis and helps dilate the uterine cervix.

LH (Luteinizing hormone) is produced by the pituitary gland in the brain. It triggers ovulation & promotes the development of the corpus luteum by rupture of the Graafian follicle and high concentration of estrogen is released by mature Graafian  follicle. The egg ruptures the ovary wall and heads into the fallopian tubes where it waits for the sperm./

Ovulation occurs when the level of hormones is as follows:
(a) High concentration of estrogens
(b) Low concentration of progesterone
(c) High concentration of LH
(d) High concentration of FSH

In follicular phase of menstrual cycle, LH and FSH increase gradually and stimulate follicular development as well as secretion of estrogens by the growing follicles.

• The motile sperms swim rapidly, pass through the cervix, enter into the uterus and finally reach the junction of the isthmus and ampulla (ampullary-isthmic junction) of the fallopian tube.
• The ovum released by the ovary is also transported to the ampullary isthmic junction where fertilization lakes place.
• Fertilization can only occur if the ovum and sperms are transported simultaneously to the ampullaryisthmic junction. This is the reason why not all copulations lead to fertilization and pregnancy.

During gametogenesis, spermatogonia are diploid because of undergoing the process of meiosis.

Spermatogenesis:

Urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids from the body. The urethra travels through the penis and carries semen as well as urine.

• A. Head → IV. Genetic materials
  The head of the sperm contains the nucleus, which holds genetic material (DNA).
• B. Middle piece → III. Energy
  The middle piece contains mitochondria, which provide energy (ATP) for movement.
• C. Acrosome → I. Enzymes
  The acrosome is a cap-like structure over the sperm head that contains enzymes (like hyaluronidase) to penetrate the egg.
• D. Tail → II. Sperm motility
  The tail (flagellum) helps in motility, allowing the sperm to swim.