Question

nitrogenous bases: - adenine - thymine - guanine - cytosine
phosphate group
nitrogenous base pairs
weak hydrogen bonds between the nitrogenous bases hold the two strands of a dna molecule together. but hydrogen bonds can only form between certain nitrogenous bases. this is called complementary base pairing. in any dna molecule, adenine pairs only with thymine, and guanine pairs only with cytosine.
complete the paragraph to describe the model.
the dna model above shows nucleotides. according to the rules of complementary base pairin 4 line always pairs with adenine

Explanation:

The DNA model shows multiple nucleotides. Complementary base - pairing rules state thymine pairs with adenine.

Answer:

The DNA model above shows multiple nucleotides. According to the rules of complementary base pairing, thymine always pairs with adenine.