Match the stages of meiosis of Column-I to their characteristic features in Column-II and select the correct option using the codes given below: Column-I a. Pachytene b. Metaphase I c. Diakinesis d. Zygotene Column-II (i) Pairing of homologous chromosomes (ii) Terminalization of chiasmata (iii) Crossing-over takes place (iv) Chromosomes align at equatorial plate
Answer: (A) a-(iii), b-(iv), c-(ii), d-(i). Answer: a-(iii), b-(iv), c-(ii), d-(i) Solution: Pachytene (a) is the stage where crossing over takes place (iii); Metaphase I (b) is where the bivalent chromosomes align at the equatorial plate (iv); Diakinesis (c) is marked by terminalisation of chiasmata (ii); and Zygotene (d) is when pairing of homologous chromosomes (synapsis) occurs (i).
- A.a-(iii), b-(iv), c-(ii), d-(i)✓
- B.a-(i), b-(iv), c-(ii), d-(iii)
- C.a-(ii), b-(iv), c-(iii), d-(i)
- D.a-(iv), b-(iii), c-(ii), d-(i)
Correct Answer
(A) a-(iii), b-(iv), c-(ii), d-(i)
Solution & Explanation
Answer: a-(iii), b-(iv), c-(ii), d-(i) Solution: Pachytene (a) is the stage where crossing over takes place (iii); Metaphase I (b) is where the bivalent chromosomes align at the equatorial plate (iv); Diakinesis (c) is marked by terminalisation of chiasmata (ii); and Zygotene (d) is when pairing of homologous chromosomes (synapsis) occurs (i). Only option A matches every stage to its correct feature. NCERT Reference: Ch 10, p.126, line 86 — "terminalisation of chiasmata. During this phase the chromosomes are"