B Nature selection for traits the allow for increased rates of reproduction and survival over traits that don't, is correct.
A is also correct
Answer:
DNA
Explanation:
Thymine is one of the four nucleobases that pairs with adenine to make up DNA, also called 5-methyluracil. It is replaced by uracil to make RNA molecules during transcription.
Theferore the unknown chemical analyzed was DNA because thymine is found in DNA and not in RNA molecules.
Answer:
No, they do not have backbones
Explanation:
