Question

Two eukaryotic proteins have one domain in common but are otherwise very different. Which of the following processes is most likely to have contributed to this similarity?

(A) Gene duplication

(B) Alternative splicing

(C) Exon shuffling

(D) Random point mutations

Short answer

1. The statement “Gene duplication” is false.
2. The statement “Alternative splicing” is false.
3. The statement “Exon shuffling” is true.
4. The statement “Random point mutation” is false.

Step-by-step solution

Protein

The macromolecule produced through the process such as transcription and translation is called protein. The arrangement of nucleotide sequence on DNA acts as codons to synthesize protein in a cell.

Every organism has its specific arrangement of nucleotide sequence to synthesize protein responsible for its phenotypic appearance and cellular functions.

Explanation of option (A)

Gene duplication is the production of more copies of genes due to mutation. The duplication of genes contributes to the process of evolution. However, it is restricted within the population of the species.

Thus, gene duplication cannot cause a similar domain in proteins.

Therefore, the given statement is false.

Explanation of option (B)

Alternative splicing regulates the diversity of protein in eukaryotic organisms. It acts on mRNA to synthesize new variant proteins by converting the genomic instructions into functional proteins.

Thus, alternative splicing increases protein diversity and does not contribute to the similarity of the protein domain in eukaryotes.

Therefore, the given statement is false.

Explanation of option (C)

Exon shuffling leads to the origin of new PPIs (protein-protein interaction) through its recurrent mechanism. In this mechanism, exons from different genes are shuffled together ectopically. It leads to the expansion of protein domains in eukaryotes such as metazoans.

Thus, exon shuffling created multidomain proteins in eukaryotes during the process of evolution.

Therefore, the given statement is true.

Explanation of option (D)

Random point mutation alters single base pairs due to mutation. The nucleotides are deleted to be switched to another location in this type of mutation. It can cause changes in a small population.

Thus, random point mutation alters codons corresponding to different amino acids and can lead to beneficial and harmful changes in the population.

Therefore, the given statement is false.