Multiple Choice
In the context of DNA structure, who is credited with discovering the base-pairing rules (A pairs with T, and G pairs with C) for DNA?
39
views
7. DNA and Chromosome Structure
DNA Structure
Multiple Choice
In the DNA double helix, how are the two complementary strands held together?
A
Ionic bonds between the sugar-phosphate backbones of the two strands
B
Hydrogen bonds between complementary nitrogenous bases (A–T and G–C)
C
Peptide bonds between nucleotides on opposite strands
D
Covalent phosphodiester bonds between bases on opposite strands
Verified step by step guidance1
Understand the structure of the DNA double helix: it consists of two strands running in opposite directions, each made up of a sugar-phosphate backbone and nitrogenous bases.
Recall that the sugar-phosphate backbone of each strand is held together by covalent phosphodiester bonds, which are strong bonds within a single strand, not between strands.
Identify the type of bonds that connect the two strands: these are the bonds between the nitrogenous bases on opposite strands.
Recognize that the bases pair specifically (A with T, and G with C) through hydrogen bonds, which are weaker than covalent bonds but strong enough to stabilize the double helix.
Conclude that the two complementary strands are held together by hydrogen bonds between the complementary nitrogenous bases (A–T and G–C).
