| Column-I (Terms) | Column-II (Explanation) | ||
| A. | Terminalization | I. | Pairing of homolologous |
| B. | Synapsis | II. | Point of attachment between homologous chromosomes. |
| C. | Chiasmata | III. | Nuclear protein complex that helps in adherence of sister chromatids and then homologous chromosomes. |
| D. | Synaptonemal complex | IV. | Shifting of chiasmata outwards complex towards the ends of a bivalent. |
A) A - IV; B - I; C - II; D - III
B) A-II; B - III; C - IV; D - I
C) A - II; B - IV; C - III; D - I
D) A - IV; B - I; C - III; D - II
Correct Answer: A
Solution :
[a] Terminalization which occurs in diakinesis stage of meiosis I, is the disappearance of chiasmata of sliding towards the tips of the chromosomes due to tight condensation. Synapsis is the pairing of two homologous chromosomes. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. The process of attachment of homologous chromosomes leads to the formation of bivalents. Chiasmata is a point at which paired chromosomes remain in contact during the first metaphase of meiosis, and at which crossing over and exchange of genetic material occur between the strands. Synaptonemal complex is formed at the region of synapsis. It is a protein structure that forms between homologous chromosomes (two pairs of sister chromatids) and is thought to mediate chromosome pairing, synapsis, and recombination.
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