Question

What would happen if a mutation occurred in the DNA such that the second codon of a polypeptide, UGC, was changed to a UAG?
(A) Nothing. The ribosome would skip that codon and translation would continue.
(B) Translation would continue, but the reading frame of the ribosomes would be shifted.
(C) Translation would stop at the second codon and no functional protein would be made.
(D) Translation would continue, but the second amino acid in the protein would be different.

Answer 1

Hint: A mutation is a change in the DNA sequence or genome of an organism. Wrong changes in DNA replication while cell division or exposure to mutagens or even due to viral infection can all cause mutations.

Step by step solution:
Mutations that are harmful can result in cancer or genetic diseases. A genetic disorder is a condition which arises due to changes in one or more genes. Cystic fibrosis is a human example. Both somatic and germ-line cells are susceptible to mutation. When an organism reproduces sexually, germ-line mutations take place in the reproductive cells (sperm or eggs) and are passed on to the offspring. A genetic mutation is brought on by the replacement of one nucleotide with another. referred to as a point variation. A particular kind of mutation that happens in DNA or the cell's genetic material is a point mutation. A single nucleotide base will be added, removed, or modified throughout this process, changing the DNA's regular structure.
Transition mutations and transversion mutations are two different forms of point mutations. Transition mutations happen when a purine base (such as adenine [A] or guanine [G]) replaces another purine base or when a pyrimidine base (such as thymine [T] or cytosine [C]) replaces another pyrimidine base. When a single base pair is added, removed, or altered in a genome, it is referred to as a point mutation. While the majority of point mutations are harmless, they can also have a variety of functional effects, such as modifications to encoded proteins or changes in gene expression.
UGC codes for cysteine whereas UAG is a stop codon and due to mutation, the translation would terminate at that site.

So, option (C) is correct.
Note: Environmental elements known as mutagens are what trigger mutations. Radiation as well as chemicals, and pathogenic agents are some examples of mutagens. Mutations may occur naturally spontaneously.