Chapter 42, Problem 1QC

Summary Introduction

To describe:

The four mechanisms that produce genetic variation as given in the statement, “sexual reproduction results in offspring that are genetically different from one another and from their parents”, and also describe if any of these four mechanisms occur in asexual reproduction.

Introduction:

The process of sexual reproduction occurs mainly in multicellular organisms in eukaryotes. Offspring is produced through meiosis and fertilization. The resultant offspring receive genetic material from their parents and they are genetically different from one another and from their parents.

Explanation of Solution

The process of sexual reproduction produces generation of offspring that are genetically different from one another. These types of genetic variation occur by following mechanisms that are as follows:

1. i. Chance mutations.
2. ii. At meiosis I, the recombination of homologous chromosomes.
3. iii. At meiosis I, random segregation of homologous chromosomes.
4. iv. The process of fertilization that involves new combinations of chromosomes.

Asexual reproduction occurs by cell division and causes origin of offspring that are clones of their parents. It occurs in the cells or single celled organisms. Mutation can occur in the asexual reproduction as in sexual reproduction.

Conclusion

The process of sexual reproduction results in offspring that are genetically different from one another and from their parents. This type of genetic variation occurs because of fertilization, recombination, homologous chromosomes and chance mutation mechanisms.