Khan Academy is great! Also, Alison (it's a website) has some free courses as well.
Answer:
D
Explanation:
DNA stands for deoxyribonucleic acid, while RNA is ribonucleic acid. Although DNA and RNA both carry genetic information, there are quite a few differences between them. This is a comparison of the differences between DNA versus RNA, including a quick summary and a detailed table of the differences
A person with darker skin produces more melanin. Those are the dark brown pigments that come from your skin, hair, or eye color.
Hope that helps. -UF aka Nadia