The Microscopic Roundworm Caenorhabditis Elegans Is a Host for the Pathogenic

Multiple Choice

The microscopic roundworm Caenorhabditis elegans is a host for the pathogenic bacterium Serratia marcescens.Researchers genetically manipulated the mating system of C.elegans, producing populations that mated either sexually or asexually (by self-fertilization) .When exposed to the S.marcescens parasite, self-fertilizing populations of C.elegans rapidly became extinct.Sexually reproducing populations survived.This suggests that, to maintain healthy populations, C.elegans requires

A) the absence of S. marcescens.
B) the presence of S. marcescens.
C) genetic variation, which allows adaptation to S. marcescens.
D) genetic uniformity, which leads to stable populations.
E) a natural ecosystem where genetic manipulation does not occur.