Question

Which base is found only in DNA? adenine guanine cytosine thymine

Answer 1

Thymine.

Step-by-step explanation:

DNA is present as the genetic material in case of almost all the organisms except some viruses only. RNA is present as the genetic material in case of the few viruses only.

DNA is made of the four nitrogenous bases, pentose deoxyribose sugar and the phosphate group. The adenine, guanine and cytosine are present in both the RNA and DNA. Thymine is present in case of the DNA only and absent in RNA and other molecule.

Thus, the correct answer is option (4).

Answer 2

Answer: The correct answer is thymine.

Step-by-step explanation:

DNA is a complex chemical compound which carries genetic information of a living being. It is a double helix structure. The full form for this is deodorize nucleic acid.

This compound is made up of 4 nitrogenous bases named as adenine (A), guanine (G), cytosine (C) and Thymine (T).

Adenine forms double hydrogen bonds with Thymine and cytosine forms triple hydrogen bonds with guanine.

`A=T\\G\equiv C`

In RNA, the nitrogenous bases found are adenine (A), guanine (G), cytosine (C) and Uracil (U).

The nitrogenous base Thymine is the only base which is found only in DNA.

Hence, the correct answer is thymine.