5. Why do males always exhibit recessive traits car-
ried on the X chromosome that they inherit from
their mothers?

males are more likely than females to an inherent a trait on the x chromosome

Explanation:

this is because males have XY chromosomes and females have XX. so if the trait is recessive, females may have it on one x but not the other. so the other x that doesn't have it is dominant and basically covers up for the trait and blocks it from being expressed. but in males, their chromosomes are XY, so they don't have an extra X to block the trait from being expressed. if they get the trait, they have it no doubt

in situ hybridization has been widely used for research applications, including clinical cytogenetics, gene mapping, tumor biology and studies of chromosome evolution.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands