Which of the following best describes the what happens during gene expression?
a. a cell reads the instructions in dna and builds a protein based on those instructions.
b. a gene is copied many times so that all of a cell s daughter cells will have their own copy.
c. the nucleus of a cell builds cellular proteins based on the sequence of the mrna code.
d. a single gene leaves the nucleus of a cell and travels through the cytoplasm to the membrane.