Chapter 10, Problem 11STP

Summary Introduction

To explain:

The time whencrossing over most likely to occur.

Introduction:

Some segments of homologous chromosomes get exchanged during synapsis. This process is called crossing over. It is a process during which chromosomal segments are exchanged between a pair of homologous chromosomes. This results in exchange of genes between homologous chromosomes.

Answer to Problem 11STP

Crossing over occurs duringprophase I of meiosis.

Explanation of Solution

Crossing over is the process by which the genetic material between non sister chromatids of homologous chromosomes is exchanged. It results in new combinations of genes in the daughter cells. During prophase I of meiosis, the homologous chromosomes align with each other and exchange some part of their chromosome so that the resultant chromosomes are recombinants- that is they have a mix of genes derived from both parental chromosomes.

Hence, crossing over occurs during prophase I of meiosis.