Offspring are rarely identical to their parents - HSC - SSCE Biology - Question 25 - 2022 - Paper 1

Genetic variation arises from different mechanisms in asexual and sexual reproduction, leading to distinct offspring traits.

Asexual Reproduction:

• Mutation: During DNA replication, mutations may occur, providing a source of genetic variation. This is typically a random process and can lead to changes in traits if they occur in a way that affects phenotype.
• Clonal Reproduction: Asexual reproduction involves processes such as binary fission or mitosis, where genetic material is copied without recombination. As a result, offspring are usually clones of the parent, leading to minimal genetic variation unless mutations occur.

Sexual Reproduction:

• Meiosis: In contrast, sexual reproduction involves meiosis, where homologous chromosomes undergo crossing over and independent assortment. These processes enhance genetic diversity by shuffling alleles and creating new combinations in gametes.
• Fertilization: The random combination of gametes from two parents during fertilization introduces further variability in offspring. Each offspring receives a unique mix of genes from both parents, resulting in greater diversity.

In summary, while asexual reproduction relies on mutations for variation, sexual reproduction utilizes genetic recombination and diverse gamete combinations to create variation among offspring.