Answer:
Male (X Chromsome)
Step-by-step explanation:
The mother is usually homozygous, meaning she has two of the same chromosome, so her offspring will get the same chromosome from her regardless. However, the father is heterozygous, meaning he has different chromsomes. Him passing down one or the either will determine the sex.
For example, in humans the mother passes the X, and then the father determines if it is a boy (passes down Y), or if it is a girl (passes down X).