Question

1. choose the best answer. what nitrogenous base always pairs with cytosine? ○ guanine ○ cytosine ○ adenine 9) choose the best answer. what type of bond holds the nitrogenous base pairs together? ○ van der waals ○ oxygen ○ metallic ○ hydrogen 10) read the descriptions. put a checkmark next to dna or rna for the matching descriptions or both dna

Explanation:

Question 8

In DNA base pairing, cytosine (C) always pairs with guanine (G) via hydrogen bonds. Cytosine can't pair with itself, and adenine pairs with thymine (or uracil in RNA). So the correct base for pairing with cytosine is guanine.

Nitrogenous base pairs in DNA (and RNA) are held together by hydrogen bonds. Van der Waals forces are weaker and not the main bond here, oxygen is an atom not a bond type, and metallic bonds occur in metals, not in base pairing. So hydrogen bonds are responsible.

Answer:

A. Guanine

Question 9