Which of the Following is a Representation of Gene Density

Question

Which of the following is a representation of gene density?
A) Humans have 2,900 Mb per genome.
B) C. elegans has ~20,000 genes.
C) Humans have ~20,000 genes in 2,900 Mb.
D) Humans have 27,000 bp in introns.
E) Fritillaria has a genome 40 times the size of a human.

Accepted Answer

Gene density is the number of genes per unit of DNA. Choice C represents the number of genes in a given amount of DNA, so it is a representation of gene density.

Answer: E 
 Genome size alone does not necessarily reflect gene density, but it can provide some information about it. In general, larger genomes tend to have lower gene density than smaller genomes. Therefore, Fritillaria having a genome 40 times the size of a human suggests that it likely has a lower gene density than humans.