Question

What is a base analogue?
a. 5-Bromouracil
b. Caffeine
c. Colchicine
d. Nitrous acid

Answer 1

Hint: Base pairing is followed up by the bonding through a common hydrogen bond. Base analogs have an almost similar structure to one of the four nitrogenous bases of DNA named as adenine, thymine, cytosine, or guanine).

Complete answer:
Base analogs are those which provide a huge contribution during the base pairing.
They are similar to the structure of the four nitrogenous bases particularly Adenine (A), guanine(G), cytosine (C), thymine (T). They generally cause mutations in the general base pairing. The mutations occur in such a way that either they do wrong base pairing or miss the correct base pairs. Hence, changes take place.

5-Bromouracil, generally (Bru) is a base analog of thymine. The general system follows up that adenine pairing up with thymine and guanine with cytosine but these analogous is the basic mutagen causing transition during replication and pairs up with guanine despite adenine.

Caffeine, the legal form of drugs used worldwide, is present in basic beverages such as tea, coffee.

Colchicine, a kind of drug that prevents gout attacks also if taken more than 6months can cause muscle damage as well.

Nitrous oxide, popularly known as laughing gas. It is non-effective and non-allergic sometimes can cause nausea.
Hence, option (A) 5-Bromouracil is the correct answer.

 Additional Information:
- Hydrogen bonds are used for base pairing.
- Mutations are an irregular disturbance caused by a regular mechanism.
- Base analogs are a common mutagen.
- There are many other types of mutations.
- The mutation leads to changes.

Note: Base analogs form similar structures as per one of the nitrogenous bases. And further on can be used in the new strand formation in the process of semi-conservative replication.