Question

number correct: 4 number incorrect: 2
what important events take place during prophase i?
i. chromatin condenses to form visible chromosomes.
ii. the nucleus and nucleolus disintegrate.
iii. homologous chromosomes pair up to form tetrads.
iv. chromosomes line up down the middle of the cell.
a. i, ii and iii
b. i only
c. i and iv
d. i, ii, iii and iv

Explanation:

To solve this, we analyze each statement about Prophase I:

• I: Chromatin condenses to chromosomes (true for prophase I).
• II: Nucleus and nucleolus disintegrate (occurs in prophase I).
• III: Homologous chromosomes pair (synapsis, forms tetrads in prophase I).
• IV: Chromosomes line up at the middle (metaphase, not prophase I).

So I, II, III are correct.

Answer:

A. I, II and III