Final answer:
Two genes on separate chromosomes, an autosome like chromosome 3 and the X chromosome, will always be unlinked. This is due to the principle of independent assortment during meiosis where genes on different chromosomes segregate independently of one another.
Step-by-step explanation:
When studying two genes where one is located on an autosome (such as chromosome 3) and the other on the X chromosome, these genes will always be unlinked. This is because genes on different chromosomes segregate independently according to Mendelian genetics. Autosomes are chromosomes that are not involved in determining sex, unlike the sex chromosomes (X and Y). Independent assortment occurs during meiosis, where each chromosome is sorted into gametes independently from chromosomes in other pairs. Thus, genes on different chromosomes will be inherited in various combinations, not necessarily the same combination as found in the parents, which defines them as unlinked. Conversely, linked genes are located on the same chromosome and are transmitted together during meiosis, unless separated by crossing-over. However, since the genes in question are on separate chromosomes (one on an autosome and one on the X chromosome), linkage does not apply to them.