__________ is the basic unit of heredity; many of them contain the code for a specific proteins. Each _____________ contains many ___________. Fill in the blanks.

Responses
A A gene; chromosome; genesA gene; chromosome; genes
B DNA; chromosome; nitrogen basesDNA; chromosome; nitrogen bases
C A chromosome; chromosome; genesA chromosome; chromosome; genes
D A chromosome; gene; DNA molecules

B A gene; chromosome; genes