During a cell's development, it differentiates. how does differentiation occur?
a. a developing cell's function is determined by the number of organelles it contains.
b. a developing cell receives hormonal messages from endocrine glands that instruct the cell's chromosomes.
c. as a cell matures, genes that are not necessary to its function are ejected out of the cell through active transport.
d. certain genes are turned on and others are turned off; this action produces adult cells that are specialized.