What nitrogen base is present in dna but absent in rna?

Construct an explanation about the function of mitosis for multicellular organisms

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

To confirm when to exclude children from school it’s recommended that you refer to guidelines from which of the following organizations