Exam 12: Processes Of Evolution

-stabilizing selection - extreme forms of a trait are eliminated,and an intermediate form is adaptive.

_____ are hot spots for the evolution of antibiotic-resistant bacteria and their spread to humans due to excessive use of antibiotics.

In Lake Victoria,hundreds of cichlid fish species arose after the lake last dried up 12,400 years ago.This is an example of ____.

A small Dutch population settled in South Africa in the 17th century and became known as Afrikaners.By chance,a few Dutch settlers carried the gene for Huntington's disease.Today,Huntington's disease occurs at a relatively high frequency in this population.This is an example of ____.

The fastest lions are able to catch prey,such as zebras; similarly,the fastest zebras are able to escape predatory lions.Over time,the lion and zebra populations become composed of faster and faster individuals.This is an example of ____.

With ____ selection,the frequency of a favored allele will increase as a phenotypic variation becomes more adaptive.

For each statement, select the genetic evolutionary concept that best represents the description. -Refers to an allele for which all members of a population are homozygous.

For each statement, select the best choice that represents the description given. -illustrated by the persistence of the sickle cell allele in areas with high rates of malaria

____ increases the frequency of adaptive mutations in a population over time.

Puppies born too large experience difficulties during birthing and tend to have respiratory and other problems.Puppies born too small often can't compete with their siblings for their mother's milk.Thus,puppies of intermediate size have a survival advantage.This is an example of ____ selection.

Exposure of wild rat populations to warfarin led to the evolution of warfarin-resistant rats.These rats had a mutated version of the VKORC1 gene,indicating that ____ had occurred in these resistant rat populations.

The appearance of lungs was a(n)____ that drove the evolution of land vertebrates.

For each statement, select the best choice that represents the description given. -bacterial populations evolve resistance to antibiotics via new traits that arise by mutation

-directional selection - the form of a trait at one end of a range of variation is adaptive.

Match the evolutionary concepts correctly with the correct description or example.Some choices may be used more than once. -Animals that have too few offspring risk that all of them will be lost to predators,and therefore,their genes will not be passed onto the next generation.Animals with too many offspring may not be able to take care of all of them.Therefore,most animals have an intermediate number of offspring.

The increased variability in the frequency of the b+ allele in the smaller flour beetle population in the graph above is an example of ____.

What is one result of the bottleneck effect?  

Match the evolutionary concepts correctly with the correct description or example.Some choices may be used more than once. -Homozygous dominant black mice are camouflaged by dark rocks and homozygous recessive light-colored mice are camouflaged by light colored rocks.Heterozygous grey mice have no camouflage and are easily picked off and eaten by hawks.

For each statement, select the best choice that represents the description given. -a quantifiable,heritable characteristic

For each statement, select the best choice that represents the description given. -the grouping of species on the basis of shared characteristics