AP BIOLOGY

Detailed explanation-1: -Attached to each sugar is one of four bases: adenine (A), cytosine (C), guanine (G) [GWA-NeeN] or thymine (T). The two strands are held together by hydrogen bonds between pairs of bases: adenine pairs with thymine, and cytosine pairs with guanine.

Detailed explanation-2: -The bases are the “letters” that spell out the genetic code. In DNA, the code letters are A, T, G, and C, which stand for the chemicals adenine, thymine, guanine, and cytosine, respectively. In base pairing, adenine always pairs with thymine, and guanine always pairs with cytosine.

Detailed explanation-3: -Under normal circumstances, the nitrogen-containing bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The binding of these base pairs forms the structure of DNA .

Detailed explanation-4: -The purines, adenine and cytosine, are large with two rings, while the pyrimidines, thymine and uracil, are small with one ring.

Detailed explanation-5: -Guanine is one of the building blocks of DNA. It’s the G in the A, C, G, or T. Guanine in the double helix pairs with cytosine, so you will see CG pairs; one on one strand and one on the other.