Which phase of blood-clotting involves smooth muscle contractions in a broken blood vessel?

a. vascular spasm
b. coagulation
c. platelet plug formation
d. fibrin formation

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

Number and variety of living organism; includes genetic, species, and ecological types

What do your cells need to live? a. carbon dioxide b. carbon c. air d. oxygen