What does it mean to say that two genes are "linked"? Can linked genes assort independently? Why or why not?

To say that two genes are "linked" means that they are located close to each other on the same chromosome. This proximity often results in these genes being inherited together during reproduction, rather than being independently assorted into different offspring.

Linked genes generally do not assort independently, meaning they are less likely to segregate and shuffle independently into different combinations during meiosis. This is because the closer two genes are to each other on a chromosome, the higher the chance that they will be inherited together as a unit.

The reason behind this is genetic recombination, the process where genetic material is exchanged between homologous chromosomes during meiosis. Recombination frequently occurs between non-sister chromatids, resulting in the shuffling and exchange of genetic material between them. However, the probability of recombination occurring between two genes decreases as the distance between them decreases. Genes that are very close or adjacent to each other have a lower chance of experiencing recombination and are more likely to be inherited together.

However, it is important to note that linked genes can still undergo independent assortment if there is a significant amount of genetic recombination occurring between them. This can happen if the genes are sufficiently far apart on the chromosome, allowing for crossing over between them during meiosis. In such cases, the genes can segregate independently into different offspring.

In summary, linked genes are those that are located close to each other on the same chromosome. They tend to be inherited together and do not assort independently, although the possibility of independent assortment increases with increased distance between the genes and the occurrence of genetic recombination.