In the Genetic Map of the Human Genome, One Map

Multiple Choice

In the genetic map of the human genome, one map unit is approximately 850,000 bp. For the genome of the eukaryotic yeast Saccharomyces cerevisiae, one map unit is approximately 3000 bp. Why is a map unit so different in these two different types of organisms?

A) A map unit is the amount of measured recombination between two linked points in a genome, and humans have more SNPs than Saccharomyces cerevisiae that can serve as genetic markers.
B) An increased number of noncoding introns in humans suppresses recombination and leads to larger physical distances for each map unit.
C) Saccharomyces cerevisiae has fewer predicted genes than humans, which means that less recombination is required in yeast cells.
D) The amount of homologous recombination per DNA length must be lower in humans than in Saccharomyces cerevisiae.
E) Humans have more chromosomes and, therefore, have more linkage groups than Saccharomyces cerevisiae.