How many hydrogen bonds hold an adenine and thymine pair together?

1. Base pairs are stabilised by hydrogen bonds, but not all pairs equally. 2. Adenine and thymine form two hydrogen bonds. 3. Cytosine and guanine form three hydrogen bonds. 4. That difference is why sequences rich in C and G are harder to separate. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 14 'DNA Structure and Function', sections 14.1-14.6_