The parent's genotypes are

and

respectively. When crossed together, all possible genotypes can be expressed. 1/4 AB blood, 1/4 A blood (heterozygous), 1/4 B blood (heterozygous) and 1/4 O blood. A Punnett square has been uploaded to support this.
Skin Pigmentation is how frogs camouflage themselves in nature
Answer:
Scientists discovered mechanisms that protect tapeworms from being digested by their host. ... They also needed a mechanism to protect themselves from intestinal substances, specifically from digestive enzymes. One of such enzymes called trypsin breaks down proteins.
Explanation:
For example:Parasites can hide away from the immune system by invading immune-privileged tissue such as the central nervous system or the eye (Bhopale 2003). Also some parasitoids place their eggs inside tissue such as the fat body that is not well patrolled by the host's immune system
I believe the anwser you are looking for is the
Cell Membrane.
It is a substance that lets things in and out of the cell