How to write female and male gametes on a punnett square?

Question

blues · Answer

The X chromosomes are marked as an X. The specific allele in question (if it's carried on the X chromosome) goes in parentheses after it. For example, if a trait A were carried on the X and a big A was the dominant allele and a little a is a recessive allele - I'd show them as X(A) and X(a).

The Y goes in as just the Y - though the Y chromosome does actually carry a couple genes, they're not important. You can think of Y chromosomes as being shrivelled up little bits of genetic material with no real genes on them, for almost all practical (and theoretic) purposes.