Covalent bonds between nucleotides in DNA are found between:

A) a phosphate group and a nitrogenous base.
B) a sugar and a nitrogenous base.
C) nitrogenous bases.
D) phosphate groups.
E) a sugar and a phosphate group.

Thank you.

To determine the answer to this question, we need to understand the structure of DNA and the components it is composed of.

DNA, also known as deoxyribonucleic acid, is made up of nucleotides. Each nucleotide contains three components: a phosphate group, a sugar molecule (deoxyribose), and a nitrogenous base.

Now, let's analyze the options:

A) In DNA, covalent bonds are not formed directly between the phosphate group and the nitrogenous base. Instead, these two components are connected by another part of the nucleotide structure.

B) Similarly, covalent bonds are not formed directly between the sugar and the nitrogenous base. Again, another part of the nucleotide structure is involved in the bonding.

C) Covalent bonds can be formed between nitrogenous bases, but this does not involve the entire nucleotide structure. Therefore, this option is not correct.

D) Covalent bonds do exist between the phosphate groups in DNA, but these bonds do not form the structure of the nucleotide itself. Therefore, this option is not correct.

E) The correct answer is, indeed, that covalent bonds are formed between a sugar (deoxyribose) and a phosphate group. These bonds create the backbone of the DNA molecule and connect the individual nucleotides together.

Therefore, the correct answer is option E) a sugar and a phosphate group.

Covalent bonds between nucleotides in DNA are found between the following options:

E) a sugar and a phosphate group.

The covalent bond between the sugar and the phosphate group forms the backbone of the DNA molecule.