Two strands of DNA are held together by hydrogen bonds between complementary base pairs. Which row in the table correctly identifies the base pair and the number of hydrogen bonds between them?
| Row | Base 1 | Base 2 | Number of hydrogen bonds |
|---|---|---|---|
| A | guanine | cytosine | 2 |
| B | adenine | thymine | 3 |
| C | adenine | thymine | 2 |
| D | cytosine | thymine | 3 |
Row A
Row B
Row C
Row D
30 exam-style questions on AQA A Level Chemistry Amino acids, proteins and DNA (A-level only), covering Amino acids (A-level only), Proteins (A-level only), Enzymes (A-level only), DNA (A-level only), and Action of anticancer drugs (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.