301. Which statement about the plasma membrane of a human sperm is correct?
ⓐ. It covers only the tail region
ⓑ. It surrounds the whole sperm cell
ⓒ. It is present only around the acrosome
ⓓ. It is absent from the head region
Correct Answer: It surrounds the whole sperm cell
Explanation: The sperm cell is enclosed by a plasma membrane over all its major regions. This includes the head, neck, middle piece, and tail. The membrane helps maintain the integrity of the cell as a whole rather than covering only one part. So it is a continuous outer boundary of the sperm.
302. Which region of the sperm would be identified if a cell shows a haploid nucleus covered anteriorly by an enzyme-containing cap?
ⓐ. Tail
ⓑ. Middle piece
ⓒ. Head
ⓓ. Neck
Correct Answer: Head
Explanation: The sperm head contains the haploid nucleus, which carries paternal genetic material. Over its anterior part lies the acrosome, which contains enzymes required during fertilisation. This combination of nucleus plus acrosomal cap is unique to the head region. The other regions are associated mainly with linkage, energy supply, or motility.
303. Which statement correctly compares the acrosome and the nucleus of a sperm?
ⓐ. Acrosome helps in penetration, whereas the nucleus carries genetic material
ⓑ. Acrosome provides energy, whereas the nucleus causes motility
ⓒ. Acrosome lies in the tail, whereas the nucleus lies in the middle piece
ⓓ. Acrosome and nucleus perform exactly the same role
Correct Answer: Acrosome helps in penetration, whereas the nucleus carries genetic material
Explanation: The acrosome contains enzymes that assist the sperm in penetrating the egg coverings. The nucleus, in contrast, contains the haploid paternal chromosomes. These two structures are both present in the head, but they perform different functions. One is mainly enzymatic, while the other is genetic.
304. A sperm reaches the vicinity of the ovum but shows very weak forward movement despite having a normal nucleus and acrosome. Which region is most likely functionally defective?
ⓐ. Head
ⓑ. Acrosome
ⓒ. Neck
ⓓ. Tail
Correct Answer: Tail
Explanation: Forward movement of the sperm depends primarily on the tail. Even if the head and acrosome are normal, reduced function of the tail can impair locomotion through the female tract. The middle piece provides energy, but the tail is the main propulsive structure. So weak forward movement points most directly to a tail-related defect.
305. In human females, oogenesis begins
ⓐ. only after menarche
ⓑ. only after fertilisation
ⓒ. during foetal life
ⓓ. after menopause
Correct Answer: during foetal life
Explanation: Oogenesis starts much earlier than spermatogenesis in humans. During foetal life, oogonia are formed and begin the sequence that leads to primary oocyte formation. This early onset is a major difference between male and female gamete formation. It shows that female germ-cell development starts before birth.
306. The cells that multiply by mitosis during foetal life in the developing ovary are
ⓐ. oogonia
ⓑ. primary oocytes
ⓒ. secondary oocytes
ⓓ. polar bodies
Correct Answer: oogonia
Explanation: Oogonia are the early female germ cells present in the foetal ovary. They undergo mitotic multiplication and increase in number before further developmental changes occur. Later, many of them enter meiosis and become primary oocytes. Thus, the proliferating germ cells at this stage are oogonia.
307. Which cell is formed when oogonia enter meiosis during foetal life?
ⓐ. Secondary oocyte
ⓑ. Ovum
ⓒ. Spermatid
ⓓ. Primary oocyte
Correct Answer: Primary oocyte
Explanation: When oogonia begin meiotic development, they are transformed into primary oocytes. This marks the next important stage in oogenesis after mitotic multiplication. The primary oocyte does not complete meiosis immediately. Instead, it remains arrested for a long period at a specific stage.
308. In human oogenesis, the primary oocyte remains arrested in
ⓐ. metaphase II
ⓑ. prophase I
ⓒ. anaphase I
ⓓ. telophase II
Correct Answer: prophase I
Explanation: Primary oocytes formed during foetal life enter meiosis but do not complete it at once. They remain arrested in prophase I for a prolonged period, often until puberty and beyond. This arrest is one of the defining features of human oogenesis. It clearly distinguishes female gamete formation from the male pattern.
309. A female germ cell has entered meiosis during foetal life but has not completed the first meiotic division and remains dormant for years. This cell is a
ⓐ. primary oocyte
ⓑ. oogonium
ⓒ. secondary oocyte
ⓓ. spermatozoon
Correct Answer: primary oocyte
Explanation: The description matches the primary oocyte, which enters meiosis during foetal life and then remains arrested in prophase I. This arrest may continue for many years until further development resumes in later reproductive life. Oogonia are earlier mitotically dividing cells, while secondary oocytes appear much later. So the dormant meiotic cell described here is the primary oocyte.
310. In the human ovary, a primary oocyte formed during foetal life is enclosed within a
ⓐ. Graafian follicle
ⓑ. tertiary follicle
ⓒ. corpus luteum
ⓓ. primordial follicle
Correct Answer: primordial follicle
Explanation: After formation, the primary oocyte becomes surrounded by follicular cells and is enclosed in a primordial follicle. This is the earliest follicular association of the female germ cell in the ovary. More advanced follicles such as tertiary and Graafian follicles appear later during follicular growth. So the earliest follicular enclosure is the primordial follicle.
311. Which sequence correctly represents the early events of oogenesis in human females during foetal life?
ⓐ. Primary oocyte → oogonium → ovum → primordial follicle
ⓑ. Oogonium → secondary oocyte → primary oocyte → Graafian follicle
ⓒ. Primordial follicle → oogonium → primary oocyte → ovum
ⓓ. Oogonium → primary oocyte → arrest in prophase I → primordial follicle
Correct Answer: Oogonium → primary oocyte → arrest in prophase I → primordial follicle
Explanation: Early oogenesis begins with oogonia in the foetal ovary. These cells enter meiosis to become primary oocytes, and then they remain arrested in prophase I. Each such primary oocyte gets surrounded by follicular cells to form a primordial follicle. This sequence captures the earliest female germ-cell events before birth.
312. Which statement correctly compares the onset of oogenesis and spermatogenesis in humans?
ⓐ. Both begin only after puberty
ⓑ. Oogenesis begins before birth, whereas spermatogenesis begins at puberty
ⓒ. Oogenesis begins after menopause, whereas spermatogenesis begins before birth
ⓓ. Both begin only after fertilisation
Correct Answer: Oogenesis begins before birth, whereas spermatogenesis begins at puberty
Explanation: Human oogenesis starts during foetal life, long before birth occurs. Spermatogenesis, in contrast, becomes active only at puberty under hormonal influence. This difference in timing is one of the clearest contrasts between male and female gamete formation. It explains why primary oocytes are already present in females at birth.
313. Which cell in the human ovary remains arrested in prophase I for a long period?
ⓐ. Primary oocyte
ⓑ. Secondary oocyte
ⓒ. Oogonium
ⓓ. Polar body
Correct Answer: Primary oocyte
Explanation: The primary oocyte is formed when oogonia enter meiosis during foetal life. It does not complete meiosis immediately and remains arrested in prophase I for many years. Secondary oocytes appear much later, around ovulation, and are arrested in a different stage. So the long prophase I arrest belongs to the primary oocyte.
314. A female germ cell in the foetal ovary has entered meiosis and is surrounded by follicular cells. This structure is best identified as a
ⓐ. seminiferous tubule
ⓑ. Graafian follicle
ⓒ. primordial follicle
ⓓ. corpus luteum
Correct Answer: primordial follicle
Explanation: Once a primary oocyte is surrounded by follicular cells, the resulting structure is called a primordial follicle. This is the earliest follicular stage in the ovary. It is established during foetal life and forms the resting stock of female germ cells. More advanced follicles arise later from these primordial follicles.
315. Assertion: Human females are born with many primary oocytes already present in their ovaries. Reason: Oogenesis begins during foetal life, and primary oocytes are formed before birth.
ⓐ. Both Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion.
ⓑ. Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.
ⓒ. Assertion is true, but the Reason is false.
ⓓ. Assertion is false, but the Reason is true.
Correct Answer: Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion.
Explanation: The assertion is correct because many primary oocytes are already present in the ovaries of a newborn female. The reason is also correct since oogenesis starts during foetal life and oogonia enter meiosis before birth. That early onset directly explains why primary oocytes are already available at birth. So the reason properly supports the assertion.
316. Which of the following is diploid and formed before birth during human oogenesis?
ⓐ. Secondary oocyte
ⓑ. Ovum
ⓒ. Polar body
ⓓ. Primary oocyte
Correct Answer: Primary oocyte
Explanation: The primary oocyte is formed from oogonia before birth and remains diploid at that stage. It has entered meiosis but has not completed the first meiotic division. Secondary oocytes, ova, and polar bodies are haploid products of later stages. Therefore the correct pre-birth diploid cell is the primary oocyte.
317. A newborn female child has ovaries containing many germ cells arrested in meiosis. These cells are mainly
ⓐ. primary oocytes
ⓑ. secondary oocytes
ⓒ. ova
ⓓ. spermatids
Correct Answer: primary oocytes
Explanation: At birth, the ovaries contain many primary oocytes that were formed during foetal life. These cells have already entered meiosis and remain arrested in prophase I. Secondary oocytes are produced much later, closer to ovulation. Thus the meiotically arrested germ cells in a newborn are primary oocytes.
318. Which structure mainly contains the resting stock of primary oocytes in the ovary before puberty?
ⓐ. Tertiary follicles
ⓑ. Corpus luteum
ⓒ. Primordial follicles
ⓓ. Ejaculatory ducts
Correct Answer: Primordial follicles
Explanation: Primary oocytes formed before birth are enclosed within primordial follicles. These primordial follicles represent the early reserve present in the ovary. They remain in this resting state until later follicular development begins after puberty. This is why the ovarian stock before puberty is mainly in the form of primordial follicles.
319. Which term correctly identifies the mitotically dividing female germ cells of the foetal ovary before they enter meiosis?
ⓐ. Primary oocytes
ⓑ. Oogonia
ⓒ. Secondary oocytes
ⓓ. Polar bodies
Correct Answer: Oogonia
Explanation: Oogonia are the earliest female germ cells involved in oogenesis. During foetal life, they multiply by mitosis and increase in number. Some of them later enter meiosis and become primary oocytes. So the mitotically dividing stage before meiotic entry is the oogonium.
320. Which pathway best represents the earliest stages of human oogenesis?
ⓐ. Secondary oocyte → ovum → polar body
ⓑ. Primary oocyte → oogonium → primordial follicle
ⓒ. Oogonium → ovum → implantation
ⓓ. Oogonium → primary oocyte → primordial follicle
Correct Answer: Oogonium → primary oocyte → primordial follicle
Explanation: The earliest stages of oogenesis begin with oogonia in the foetal ovary. These become primary oocytes after entering meiosis, and each primary oocyte gets enclosed by follicular cells to form a primordial follicle. This pathway captures the pre-birth sequence of female germ-cell development. It is the simplest correct text conversion of the early oogenetic events.
