Question

When DNA is replicated, it is necessary for the two strands to "unzip" temporarily. Choose which bonding type is most appropriate for holding the strands together in this way.
A) ionic bonding
B) hydrogen bonding
C) non-polar covalent bonding D) polar covalent bonding

Answer 1

Answer: B) hydrogen bonding

Explanation:

A) An ionic bond is formed when an element completely transfers its valence electron to another element.

B) Hydrogen bonds are special type of dipole dipole forces which are formed when hydrogen bonds with an electronegative element.

DNA strands are held together by hydrogen bonds between the bases on one strand and those on the other. Adenine and thymine have two hydrogen bonds between them while cytosine and guanine have three hydrogen bonds between them.

C) Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms.

D) A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.