Possible answers: a. solid, liquid, gas. b. density. c. Something that causes allergies. d. deoxyribonucleic acid. e. It helps them survive. f. inheritance. g. blood cells. h. allow growth.

Fact 1: Chromosomes are coiled structures made of DNA and proteins. Fact 2: DNA is deoxyribonucleic acid. Given the two facts above, chromosomes are coiled structures made of proteins and what?
Answer:
d.