Which three processes during meiosis contribute to genetic variation among organisms?

• A. Independent assortment, crossing over, and random fertilization
• B. DNA replication, mitosis, and cytokinesis
• C. Mutation, translation, and transcription
• D. Binary fission, budding, and conjugation

Answer: (A)

Verified step by step guidance

1. Understand the context of meiosis: Meiosis is a type of cell division that reduces the chromosome number by half, creating four haploid cells. It is essential for sexual reproduction and contributes to genetic variation.
2. Identify the processes that occur during meiosis and contribute to genetic variation: These include independent assortment, crossing over, and random fertilization. These processes ensure that offspring have a unique combination of genetic material.
3. Explain independent assortment: During metaphase I of meiosis, homologous chromosomes align randomly at the metaphase plate. This random alignment determines which chromosomes end up in each gamete, contributing to genetic variation.
4. Explain crossing over: During prophase I of meiosis, homologous chromosomes exchange genetic material at points called chiasmata. This recombination creates new combinations of alleles on each chromosome, increasing genetic diversity.
5. Explain random fertilization: After meiosis produces gametes, the combination of one sperm and one egg during fertilization is random. This randomness further contributes to genetic variation among offspring.