Question

Assume that an organism exists in which crossing over does not occur, but that all other processes associated with meiosis occur normally. Consider how the absence of crossing over would affect the outcome of meiosis. If crossing over did not occur, which of the following statements about meiosis would be true? Select all that apply

Answer 1

Answer:

The question lacks options, the options are:

1. The two daughter cells produced in meiosis I would be identical.

2. There would be less genetic variation among gametes.

3. The two sister chromatids of each replicated chromosome would no longer be identical.

4. The daughter cells of meiosis I would be diploid, but the daughter cells of meiosis II would be haploid.

5. Independent assortment of chromosomes would not occur.

6. The four daughter cells produced in meiosis II would all be different

The answer is 2

Explanation:

Meiosis is a kind of cell division that results in four daughter cells with each having half number of chromosomes as the parent cell. It is the cell division sexually-reproducing organisms undergo to produce gametes. Meiosis is the only cell division in which the process of CROSSING-OVER occurs.

Specifically in the Prophase stage of Meiosis I, equal chromosomal segments are exchanged between homologous chromosomes (similar but non-identical chromosomes received from each parent). This process is called CROSSING-OVER or recombination. In this process, alleles on non-sister chromatids are exchanged in a way to bring about genetic variation in the resulting gametes i.e. gametes with different combinations of alleles.

If crossing-over does not occur, the gametes will contain the exact alleles that segregated from each parent, hence, genetic variation will be reduced.