Chapter 10, Problem 10STP

Summary Introduction

To explain:

The location where crossing over could occur on the given pair of chromosomes

Introduction:

During prophase I of meiosis, the homologous chromosomes are held tightly together along their lengths. 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 10STP

Crossing over could occur between segments B − G and D − E.

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.

From the given figure it can be concluded that crossing over can occur between various segments such as between A and G, A and H, B and H, C and E, C and F, B and G, D and E and between D and F but actually crossing over occurs between segments that are close to each other. Hence, the segments that can undergo crossing over are B − G and D − E.