Which Statement best explains the evolutionary advantage of meiosis?

Options

A. Meiosis is necessary for sexual reproduction
B. Genetic recombinations are possible from generation to generation
C. Meiosis aftermates with mitosis for generation to generation
D. The same genetic system is passed on from generation to generation.

Answer

**Step-by-Step Text Solution:**

1. **Understanding Meiosis**: Meiosis is a specialized type of cell division that occurs during the formation of gametes (sperm and egg cells) in sexual reproduction. It reduces the chromosome number by half, resulting in haploid cells.

2. **Importance of Chromosome Number**: In humans, for example, somatic cells have 46 chromosomes (diploid). During meiosis, the chromosome number is halved to 23 (haploid) in the gametes. This reduction is crucial so that when fertilization occurs, the resulting zygote restores the diploid number of chromosomes.

3. **Process of Meiosis**: Meiosis consists of two sequential divisions: Meiosis I and Meiosis II. During Meiosis I, homologous chromosomes are separated, and during Meiosis II, sister chromatids are separated. This results in four genetically distinct haploid cells.

4. **Genetic Recombination**: One of the key evolutionary advantages of meiosis is genetic recombination, which occurs during the prophase of Meiosis I. Here, homologous chromosomes can exchange genetic material through a process called crossing over. This leads to new combinations of genes in the gametes.

5. **Evolutionary Advantage**: The mixing of genetic material through recombination increases genetic diversity in a population. This diversity is beneficial for evolution, as it provides a wider range of traits that may enhance survival and adaptation to changing environments.

6. **Conclusion**: Among the statements provided regarding the evolutionary advantage of meiosis, the best explanation is that meiosis allows for genetic recombination from generation to generation. This process ensures that each generation has unique genetic combinations, which is vital for evolution and adaptation.

**Final Answer**: The statement that best explains the evolutionary advantage of meiosis is that genetic recombinations are possible from generation to generation.

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