For offspring to have a recessive trait, what has to be true? (a) both parents had to give a recessive trait to their offspring
(b )one parent had a recessive allele to pass on but the other parent only had dominant alleles
(c) both parents had only dominant alleles

Which of the following describe the role a biochemical pump plays in active transport? a it prevents water from moving across the cell membrane. b it uses energy to move materials across the cell membrane against the concentration gradient. c it large molecules cross the cell membrane without using energy. d it a cell move molecules from an area of higher concentration to an area of lower concentration.