Question

answers each question.

1. a cell is going through meiosis. the sister chromatids are lined up on the metaphase plate. what phase of meiosis is this?
2. an adult organism has 60 chromosomes, or 30 homologous pairs of chromosomes. 30 are maternally derived, 30 are paternally derived. how many chromosomes are in each cell after meiosis?
3. what is the purpose of the crossing - over portion of meiosis?

to create genetically similar cells.
30 60
to create genetically diverse cells.
metaphase ii metaphase i

Explanation:

1. In meiosis, sister chromatids line up on the metaphase plate during Metaphase II (homologous pairs line up in Metaphase I).
2. Meiosis reduces chromosome number by half; a 60-chromosome organism produces cells with 30 chromosomes.
3. Crossing-over swaps genetic material between homologous chromosomes, increasing genetic diversity.

Answer:

1. Metaphase II
2. 30
3. To create genetically diverse cells.