Evolution Review Question

A scientist designed an experiment in which one chromosome from the nematode C. elegans was followed for 50 generations. What will the scientist observe if recombination contributes to the evolution of C. elegans?

• The antibiotic caused a mutation in the bacteria’s RNA.

• The antibiotic caused a mutation in the bacteria’s RNA.

• The bacteria began reproducing at a faster rate than before the antibiotic treatment.

• A small population of antibiotic-resistant bacteria were present before the treatment, and natural selection increased their frequency.

The wing color of a population of moths darkens over time. Whichstatement best explains why the wing color changes?

• An excess of smoke in the atmosphere caused the wings to darken.

• A decreased amount of water in the area caused the wings to darken.

• The frequencies of alleles for light wings was increased in the moth population.

• The frequencies of alleles for dark wings was increased in the moth population.

Which choice best demonstrates how natural selection can occur within a population?

• Competition within the population decreases because of unlimited resources.

• The organisms in the population experience genetic stability with regard to physical traits.The organisms in the population experience genetic stability with regard to physical traits.

• The number of organisms in the population decreases because of a limited number of births.The number of organisms in the population decreases because of a limited number of births.

• Females choose mates based on the brightness of the coloration of males within the population.

Which mechanism has the least effect on natural selection over time?

• mutation

• inheritance

• asexual reproduction

• environmental change

A patient has a severe bacterial infection. Within a few weeks oftreatment with an antibiotic, the bacterial population consists entirely of antibiotic-resistant bacteria. How can this outcome most likely beexplained?

• The antibiotic caused a mutation in the bacteria’s RNA.

• The bacteria began reproducing at a faster rate than before the antibiotic treatment.

• The antibiotic created resistance in the bacteria, and the bacteria are passing the resistance to one another.

• A small population of antibiotic-resistant bacteria were present before the treatment, and natural selection increased their frequency.