Question

48.

Which chemical is not found in DNA nucleotides?
thymine
guanine
ribose
deoxyribose

Answer 1

ribose. it’s simple. you can immediately eliminate deoxyribose because DNA stands for deoxyribonucleic acid. and thymine and guanine are nitrogen bases which are found in DNA.

Answer 2

Ribose

Step-by-step explanation:

DNA is a large molecule, a type of nucleic acid which store and act as a genetic material of the cell. DNA molecule is formed by the repeating monomer units called nucleotides.

Each nucleotide is made up of three subunits as:

1. 5-C sugar: De-oxyribose formed by the removal of oxygen group from 2' OH group of ribose. Ribose is the sugar molecule present in RNA nucleic acid.

2. Phosphate group (PO₄³⁻)

3. Nitrogenous bases: adenine, guanine, adenine and cytosine.

Thus, ribose is the correct answer.