Final answer:
Independent assortment occurs when genes are on different chromosomes or far apart on the same chromosome, resulting in four equally likely types of gametes. Linkage refers to genes that are close together on the same chromosome, leading to lower recombination frequencies as they tend to be inherited together.
Step-by-step explanation:
The independent assortment frequencies and linkage frequencies are key concepts in genetics, particularly when analyzing a two locus cross. If two genes are on different chromosomes or far apart on the same chromosome, they will typically exhibit independent assortment during meiosis, which means that the alleles of one gene will sort into gametes independently of the alleles of the other gene. Therefore, in the F2 generation of a dihybrid cross, where we consider seed color and seed texture in pea plants, four types of gametes are equally likely: YR, Yr, yR, and yr.
On the other hand, linkage refers to genes that are located close together on the same chromosome and tend to be inherited together. For linked genes, crossing over between them is less frequent, which means that recombination frequencies will be lower than 50%. The closer the genes are to each other, the less likely they are to be separated by a crossing-over event, and therefore, the lower the recombination frequency.