What does population density measure? 1 . the different species in a community2 . the area occupied by a population3 . the number of individuals in a sample 4. the degree of crowding of a population

Does the sun release radiant energy?

Amino acids contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. of the 20 amino acids found in humans, 11 are called "nonessential" because they can be manufactured by the body when needed. which elements in these 11 amino acids are commonly obtained from the metabolism of sugar molecules?

Most of the carbon on earth is stored in the form of