試題詳解

43. Scientists studying the SNPs (single nucleotide polymorphisms) in the human genome have found that groups of SNPs tend to be inherited together in blocks known as haplotypes. What explains this observation?
(A) Independent assortment during meiosis.
(B) Crossing over is a random event, and the chance of it occurring between two loci increases with distance; SNPs located very close to each other are genetically linked and rarely separated by crossing over.
(C) The presence of many protein-coding genes located in these regions.
(D) Random mutations occurring at the same rate across the genome.
(E) Natural selection favoring the inheritance of specific SNP combinations.