Meiosis contributes to genetic variation in plants by creating new combinations of genes in the reproductive cells (gametes). This variation helps plants adapt to different environments and supports evolution.
Here’s how meiosis increases genetic variation:
1. Crossing over:
During the early stage of meiosis (prophase I), paired chromosomes exchange segments of DNA. This process mixes the genes between maternal and paternal chromosomes, creating new gene combinations.
2. Independent assortment:
When chromosomes separate during meiosis I, each pair divides randomly. This means the resulting gametes get different combinations of maternal and paternal chromosomes, leading to many possible genetic outcomes.
3. Formation of haploid cells:
Meiosis reduces the chromosome number by half, producing haploid cells (gametes). When two gametes fuse during fertilization, they form a new diploid cell with a unique genetic combination.
4. Random fertilization:
Each pollen grain and egg cell carries different genetic material. When fertilization occurs, any pollen can combine with any egg, further increasing variation.
In short, meiosis creates genetic diversity in plants through crossing over, independent assortment, and random fertilization, ensuring that each new plant is genetically unique.