Answer:
20:Yes,individual #1 is XBXb,as the mother passes on the recessive Xb to her sons. The son individual #2 in generation 2 is affected by the recessive gene which he can only inherit from his mother.
21:mother
22:Sex-linked are Gene's carried on the sex Gene's chromosomal pair 23 whereas autosomal can be carried by any of the other 22 chromosomal pairs.
23:one
24:Yes
100% shaded,all 3 individuals
Homozygous dominant(HH) crossed with homozygous recessive (hh) yields a probability of 100% Hh.
