Each member of a class sampled a piece of ptc testing paper. thirty people sampled the chemical. twenty persons were tasters. how many had heterozygous genes? 10 20 0-20 indeterminate

Which substance contains thylakoids? a) nadph b)atp c)stroma d)chloroplast

Ecology can best be described as the study of what

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems