To assist the investigators with the crime, you will need to perform Polymerase Chain Reaction (PCR) to create copies of this gene so the sizes can be compared to determine if the blood was from a man or woman. During PCR it will be necessary to break the hydrogen bonds of the base pairs. Where are those hydrogen bonds normally found?

a. Between two nitrogen-containing bases in a single strand of DNA.

b. Between the phosphate and sugar of the same nucleotide.

c. Between the sugar of one nucleotide and the phosphate of a different nucleotide.

d. Between one nitrogen-containing base on a single strand of DNA and another nitrogen-containing base on the complementary strand of DNA.

e. Between one phosphate on a single strand of DNA and a sugar on the complementary strand of DNA

d. Between one nitrogen-containing base on a single strand of DNA and another nitrogen-containing base on the complementary strand of DNA.

Explanation:

Polymerase Chain Reaction serves to make copies of a small amount of DNA. To perform the process of replication, the sample DNA molecule must be denatured. It means that the hydrogen bonds that hold the two DNA strands of the double helix together should be broken down.

A double-stranded DNA molecule has two DNA strands. The nitrogenous base of nucleotides of one DNA strand of a helix makes hydrogen bonds with a complementary base present on the other DNA strand. Adenine base makes two hydrogen bonds with thymine base while guanine makes three hydrogen bonds with cytosine. In this way, hydrogen bonds between the complementary bases of two DNA strands hold them together in a double helix.