Adenine always pairs with Thymine, and Cytosine always pairs up with Guanine in DNA. When dealing with RNA, however, Uracil replaces Thymine. So in RNA, A pairs with U and C pairs with G. (just a fun fact) :)
I'd say protein synthesizer.
Answer:
An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. (Draw a plant and this is tghe one you underline)
A heterotroph is an organism that eats other plants or animals for energy and nutrients. (You can draw a dog, cat, frog or a person)
D is the answer. A gene is a part of a chromosome.