Practice question

Question

Given below are the few statements on concepts related to genome evolution. A. Presence of introns in some chloroplast genes suggests that endosymbiosis (leading to organelle evolution) occurred before loss of introns in prokaryotes and supports the hypothesis that genes originated as interrupted structures. B. Negative selection is associated with increased rate of nonsynonymous substitutions as compared to synonymous substitutions. c. Nucleotide substitution rates during evolution can be inferred from divergence of the sequences that are non-functional or neutral. D. Positive selection is associated with increased rate of nonsynonymous substitutions as compared to synonymous substitutions. Which one of the following options represents a combination of all INCORRECT statements?