Question

Refer to the following statements describing Prophase I of meiosis and answer the question.
(i) Thin thread like chromosomes with a beaded appearance
(ii) Appearence of recombination nodules
(iii) Formation of bivalents/tetrads
(iv) Terminalisation of chiasmata
(v) Appearance of chiasmata
Arrange the given statements in the correct sequence of their occurrence during prophase I.

• A. (i), (iii), (ii), (v), (iv)
• B. (i), (ii), (iii), (iv), (v)
• C. (i), (iv), (v), (ii), (iii)
• D. (i), (iii), (ii), (iv), (v)

Answer 1

Answer: (A)

Prophase is the longest phase of karyokinesis of meiosis and it is divided into 5 phases. Leptotene is the stage where the chromosome appears as a long thread with chromosomes on it. Then we have zygotene where bivalents or tetrads are seen are seen. Pachytene is the state where the crossing over and the formation of recombinant nodules takes place. Diplotene is a stage where the chiasmata and the X-shaped structure are seen. Diakinesis is the where terminalisation takes place.

Thus, the correct answer is '(i), (iii), (ii), (v), (iv).'