Arrange the following cell layers/structures around the female gamete, from outer to inner side:
A. Zona pellucida
B. Perivitelline space
C. Corona radiata
D. Plasma membrane of ovum
Choose the correct answer from the options given below:
A.C, A, D, B
B.C, A, B, D
C.D, B, A, C
D.A, C, B, D
Solution & Explanation
Core Logic
The cell layer/structure around the female gamete from outer to inner side is:
Corona radiata (C) arrow$\rightarrow$ Zona pellucida (A) arrow$\rightarrow$ Perivitelline space (B) arrow$\rightarrow$ Plasma membrane of ovum (D).
So the correct answer is C, A, B, D.
Oogenesis and Ovum Structure diagram for Q161 - NEET 2024 Morning
Pattern Recognition
Corona radiata is the outermost cellular layer. Zona pellucida is the acellular layer beneath it. The perivitelline space separates the zona from the actual plasma membrane of the oocyte.
A. The foetus movement starts and hair appears on the head
(I) 24 weeks of pregnancy
B. The foetus develops limbs and digits
(II) 20 weeks of pregnancy
C. The foetus develops external genital organs
(III) 8 weeks of pregnancy
D. The foetus body is covered with fine hair; eyelids separate and eyelashes are formed
(IV) 12 weeks of pregnancy
The image likely acts as a visual distractor or supplementary table provided in the paper relating to embryonic milestones.
Choose the correct answer from the options given below:
According to the human embryonic development timeline:
By the end of the second month (8 weeks), the foetus develops limbs and digits (B-III).
By the end of 12 weeks (first trimester), most major organ systems are formed, including well-developed external genital organs (C-IV).
During the fifth month (approx. 20 weeks), the first movements of the foetus and appearance of hair on the head are observed (A-II).
By the end of 24 weeks (second trimester), the body is covered with fine hair, eyelids separate, and eyelashes are formed (D-I).
Step 1: Final Conclusion
The correct matches are A-II, B-III, C-IV, D-I.
Pattern Recognition
Movement & head hair = 5th month / 20 weeks (A-II). Limbs & digits = end of 2nd month / 8 weeks (B-III). Match these two and the correct option is clear.
Chapter Mix
Class 12 Biology: Human Reproduction
Q143neet_2026_03_may_morningGametogenesis
Spermatogonia undergo a series of cell divisions statements to produce sperms. Select the correct from the following :
A. Spermatogonia always undergo meiotic cell division.
B. Primary spermatocytes divide mitotically to produce secondary spermatocytes.
C. Secondary spermatocytes, through their second meiotic division, produce haploid spermatids.
D. Spermatids produce spermatozoa through mitosis.
E. Spermatids transform into spermatozoa by spermiogenesis.
Choose the correct answer from the options given below:
A. C and E only
B. A, C and E only
C. B, C and D only
D. A and E only
Solution
Core Logic
Let's review the spermatogenesis process:
A is incorrect: Spermatogonia multiply by mitotic division to increase their numbers, not meiosis.
B is incorrect: Primary spermatocytes undergo the first meiotic division (reduction division) to form secondary spermatocytes.
C is correct: Secondary spermatocytes undergo the second meiotic division to form haploid spermatids.
D is incorrect: Spermatids do not undergo mitosis. They undergo cellular differentiation.
E is correct: The transformation process of spermatids into mature spermatozoa (sperms) is called spermiogenesis.
Step 1: Final Conclusion
The correct statements are C and E only.
Pattern Recognition
Gonia = Mitosis. Primary -> Secondary = Meiosis I. Secondary -> Spermatids = Meiosis II. Spermatids -> Spermatozoa = Spermiogenesis (differentiation, not division).
Chapter Mix
Class 12 Biology: Human Reproduction
More Human Reproduction Questions — neet_2026_03_may_morning
Practice past-year questions one chapter at a time. Pick an exam → subject → chapter and get every PYQ for that topic — pulled together from all past papers — with the chapter's key formulas alongside.
