Question

Arrange the following events of meiosis in the correct sequence.
(i) Crossing over

(ii) Synapsis
(iii) Terminalization of chiasma
(iv) The disappearance of the nucleolus.

• A. $\left(ii\right),\left(i\right).\left(iv\right).\left(iii\right)$
• B. $\left(ii\right),\left(i\right).\left(iii\right).\left(i\right)$
• C. $\left(i\right),\left(ii\right).\left(iii\right).\left(iv\right)$
• D. $\left(ii\right),\left(iii\right).\left(iv\right).\left(i\right)$

Answer 1

The correct option is A $\left(ii\right),\left(i\right).\left(iv\right).\left(iii\right)$

• Five stages of prophase include:-

1. Leptotene- condensation of chromatin or chromatin fibers.

2. Zygotene- synapsis occurs with synaptonemal complex being formed between homologous chromosomes.

3. Pachytene- crossing over of different chromatids

4. Diplotene- homologous chromosomes starts to separate from each other (disjunction), chiasmata appears (junction between chromosomes)

5. Diakinesis- chromosomes are fully condensed, nucleolus disappears and nuclear membrane disintegrates.

• The correct answer is OPTION A.