Question

Explain the mechanism of crossing over that occurs during meiosis.​

Answer 1

Answer:

Crossing-over is the process by which homologous chromosomes exchange segments with each other. It occurs most often during the first meiotic division. When prometaphase begins, each chromosome has been duplicated to form two identical sister chromatids.

Answer 2

Answer:

The DNA strands must be broken to exchange their segments. The portions of the chromosome that undergo crossing over contain the same gene loci. Crossing-over leads to the recombination of the genes on the chromosomes. The point of crossover is visible as a cross-shaped chiasma.

The exchange is usually reciprocal – the exchanging segments of the two chromosomes are of similar size--, but crossing over can sometimes be unequal. Crossing over can occur at several locations between a synapsing pair of homologous chromosomes. Crossing-over may be:

single crossing-over;

double crossing-over;

multiple crossing-over.

I hope this answer is helpful