An organism's cells have two pairs of homologous chromosomes. How many genetically different gametes are possible? What happens during metaphase I that leads to genetic variation ir gametes?

organism with two pairs of homologous chromosomes (meaning it has a total of 4 chromosomes) can produce **4** genetically different gametes.<br /><br />Here's why:<br /><br />* **Independent Assortment:** Each homologous pair of chromosomes can align in two different ways during metaphase I of meiosis. With two pairs, the possibilities multiply: 2 (arrangements for pair 1) * 2 (arrangements for pair 2) = 4 possible combinations in the resulting gametes.<br /><br />**What happens during Metaphase I that leads to genetic variation?**<br /><br />During Metaphase I, the homologous chromosome pairs line up along the metaphase plate. The key to genetic variation is that the orientation of each pair is *random* – **independent assortment**. One chromosome from each homologous pair will end up in each daughter cell. Since the alignment is random, the combination of maternal and paternal chromosomes that end up in each gamete is also random. This shuffling of chromosomes creates genetic diversity in the resulting gametes.<br />