AP BIOLOGY

Detailed explanation-1: -DNA base pair. 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-2: -The Adenine-Thymine base pair is held together by 2 hydrogen bonds while the Guanine-Cytosine base pair is held together by 3 hydrogen bonds. That is also the reason why the two strands of a DNA molecule can be separated more easily at sections that are densely populated by A-T base pairs.

Detailed explanation-3: -Nitrogenous bases present in the DNA can be grouped into two categories: purines (Adenine (A) and Guanine (G)), and pyrimidine (Cytosine (C) and Thymine (T)).

Detailed explanation-4: -Base Pair The two strands are held together by hydrogen bonds between pairs of bases: adenine pairs with thymine, and cytosine pairs with guanine. National Human Genome Research Institute. 38.1K subscribers.

Detailed explanation-5: -Guanine and thymine are similarly incompatible. A always pairs with T and G always pairs with C because these are the only combinations that allow for hydrogen bonding to occur, given the spatial constraints of the double helix, which requires there to be one purine and one pyrimidine in each base pair.