Chapter 20, Problem 1CONQ

Describe the similarities and differences between homologous recombination involving sister chromatid exchange (SCE) and that involving homologs. Would you expect the same types of proteins to be involved in both processes? Explain.

Summary Introduction

To review:

The similarities and differences between the recombination and the sister chromatid exchange in respect of homologs. The explanation about the same type of proteins that are involved in these processes.

Introduction:

Amino acids are the building blocks of proteins that play a significant role in an organism’s body by carrying out many functions like providing structure to the cells and help in regulating the mechanism of organs and tissues. The chemical composition of proteins was first described by Gerardus Johannes Mulder.

Explanation of Solution

Homologous recombination is a type of genetic recombination, which helps in repairing of breaks inside DNA (deoxyribonucleic acid) strands. In this process, the sequences of nucleotides are exchanged between the two identical molecules of DNA. The sister chromatid exchange is a type of exchange, in which the exchange of genetic material occurs between the two similar sister chromatids. The similarities and differences between homologous recombination and sister chromatid exchange are given below:-

Differences:-

Homologous recombination	Sister-chromatid exchange
Homologous recombination gives rise to new allele combinations, after the crossing over process	Sister chromatid exchange no new allele formation occurs because the chromatids are similar.

Similarities:-

The sister chromatid exchange and homologous recombination show some similarities at their molecular level. In both the processes, the segment of genetic material or DNA first follows the lineup part and then undergo the crossing over process, in this way they show resemblance.

The sister chromatid exchange and homologous recombination show resemblance at the molecular level, so, both the processes involve the same type of proteins for carrying their role.

Conclusion

Therefore, it can be concluded that both processes show some similarities and resemblances on different levels, and it is estimated that both the processes are carried out by the same type of proteins.