DNA consists of .....1..... strands twisted around one another. The strands contain chemicals known as .....2..... . These chemicals join to form .....3....., with A pairing with T and C pairing with G. Which words correctly fill gaps 1, 2 and 3?
- Athree; amino acids; cross-links
- Btwo; bases; cross-links
- Cthree; bases; proteins
- Dtwo; amino acids; proteins