Which of the Following is Evidence of Gene Reduction

Question

Which of the following is evidence of gene reduction?
A) altered GC content
B) different codon usage
C) pseudogenes
D) genomic islands
E) transposons

Accepted Answer

Pseudogenes are non-functional copies of functional genes that have undergone mutations, leading to loss or reduction of function. Therefore, the existence of pseudogenes is evidence of gene reduction. The other options are not necessarily evidence of gene reduction - altered GC content can be due to other factors, different codon usage can be advantageous for a particular organism or trait, genomic islands can contain novel genes, and transposons are mobile genetic elements that can move genes around rather than reducing them.