D. One sex has a higher chance to inherit it than the other (male).
These can be either recessive or dominant. We usually think more of the recessive traits like color blindness and hemophilia but dominant sex-linked traits also exist (fragile X).
Enzymes. There are 3 main types: Peptidase, Lipase, and amylase :) hope that helps! I'm learning that stuff too :)
Predation
It can be explained in that way or also called Predatory/prey relationships.
Parasitism is when one is benefited and the other harmed (ie leech and human)
Commensalism is when one is benefited and the other not affected (Tree frog and rainforest tree)
Mutualism is when both are benefited (Bee eats honey and Flower is pollinated).