What is the function of a food vacuole?

Would really appreciate it, i have an idea but not completely sure

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

Acertain species of fish can have either long or short fins. the allele for long fins is dominant over the allele for short fins. a heterozygous, long-finned fish is crossed with a homozygous, short-finned fish. of the offspring, will have long fins and be , and will have short fins and be .