Asexual reproduction involves one parent and produces genetically diverse offspring. Variations in offspring from sexual reproduction arise from the fusion of gametes with different genetic information and the recombination of chromosomes during meiosis.
Two points of difference between asexual and sexual reproduction:
1. Number of Parents:
Asexual reproduction occurs with only one parent, whereas sexual reproduction involves two parents.
2. Offspring Genetic Similarity:
Asexual reproduction produces offspring that are genetically identical to the parent and to each other, while sexual reproduction produces offspring that are genetically unique and differ from each other and their parents.
Why variations are observed in offspring from sexual reproduction:
Fusion of Gametes:
In sexual reproduction, offspring receive genetic information from both parents through the fusion of male and female gametes. This fusion combines different sets of genetic material, leading to variations in the offspring.
Meiosis and Recombination:
During meiosis, the formation of gametes involves crossing over, where homologous chromosomes exchange segments of DNA. This genetic recombination further increases genetic diversity among the offspring.
Independent Assortment:
During meiosis, chromosomes align and separate randomly, resulting in different combinations of maternal and paternal chromosomes in each gamete. This independent assortment contributes to genetic variation among offspring.
Mutations:
DNA replication can introduce errors or mutations, which can be passed down to offspring, further contributing to variations.