What kinds of diseases can vaccinations prevent?

a.) viral diseases only

b.) any infectious disease

c.) bacterial diseases only

d.) genetic diseases only

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit. there is a precise compatibility between the active site and the lactose molecule. specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed. reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.

Why do mountaineers become breathless as they reach high altitudes

The hypothesis that evolution occurs at an irregular rate through geologic time is known as: directional evolution directional equilibrium punctuated equilibrium punctuated evolution