What is a trophic level

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen

Which macromolecule catalyzes chemical reactions this be considered enzyme chemical reactions thus he considering enzymes

If a cell is placed into a hypertonic environment,what will happen to it ? a)it will shrink or shrivel b)nothing c)it will burst d) it will expand or enlarge