Biology

Eldra P. Solomon, Charles E. Martin, Diana W. Martin,

Chapter 19

Evolutionary Change in Populations - all with Video Answers

Educators

Chapter Questions

Problem 1

The genetic description of an individual is its genotype, whereas the genetic description of a population is its
(a) phenotype (b) gene pool (c) genetic drift (d) founder effect (e) changes in allele frequencies

Sydney Reibschied

Sydney Reibschied

Numerade Educator

Problem 2

?n a diploid species, each individual possesses (a) one allele for each locus (b) two alleles for each locus (c) three or more alleles for each locus (d) all the alleles found in the gene pool
(e) half of the alleles found in the gene pool

Josee Pacheco

Numerade Educator

Problem 3

The MN blood group is of interest to population geneticists because (a) people with genotype MN cannot receive blood transfusions from either $M M$ or $N N$ people (b) the $M M, M N$ and $N N$ genotype frequencies can be observed directly and compared with calculated expected frequencies (c) the $M$ allele is dominant to the $N$ allele (d) people with the $M N$ genotype exhibit frequency-dependent selection (e) people with the $M N$ genotype exhibit heterozygote advantage

Josee Pacheco

Numerade Educator

Problem 4

If a population's allele and genotype frequencies remain constant from generation to generation, (a) the population is undergoing evolutionary change (b) the population is said to be at genetic equilibrium (c) microevolution has taken place
(d) directional selection is occurring, but only for a few generations (e) genetic drift is a significant evolutionary force

Mathew Botros

Montclair State University

Problem 5

Analysis of DNA sequences for a particular locus among individuals within a population provides biologists with one way to estimate (a) genetic drift (b) genetic polymorphism
(c) gene flow (d) heterozygote advantage (e) frequencydependent selection

Sydney Reibschied

Sydney Reibschied

Numerade Educator

Problem 6

The continued presence of the allele that causes sickle cell anemia in areas where falciparum malaria is prevalent demonstrates which of the following phenomena?
(a) inbreeding depression (b) frequency-dependent selection (c) heterozygote advantage (d) genetic drift (e) a genetic bottleneck

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 7

According to the Hardy-Weinberg principle, (a) allele frequencies are not dependent on dominance or recessiveness but remain essentially unchanged from generation to generation (b) the sum of allele frequencies for a given locus is always greater than 1 (c) if a locus has only one allele, the frequency of that allele is zero (d) allele frequencies change from generation to generation (e) the process of inheritance, by itself, causes changes in allele frequencies

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 8

The Hardy-Weinberg principle may be applicable if (a) the population size is small (b) migration occurs only at the beginning of the breeding season (c) mutations occur at a constant rate (d) matings occur exclusively between individuals of the same genotype (e) natural selection does not occur

Sydney Reibschied

Sydney Reibschied

Numerade Educator

Problem 9

Mutation (a) leads to adaptive evolutionary change (b) adds to the genetic variation of a population (c) is the result of genetic drift (d) almost always benefits the organism (e) a and b

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 10

Which of the following is not true of natural selection?
(a) natural selection acts to preserve favorable traits and eliminate unfavorable traits (b) the offspring of individuals that are better adapted to the environment will make up a larger proportion of the next generation (c) natural selection directs the course of evolution by preserving the traits acquired during an individual's lifetime (d) natural selection acts on a population's genetic variability, which arises through mutation (e) natural selection may result in changes in allele frequencies in a population

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 11

If all copies of a given locus have the same allele throughout the population, the allele frequency is (a) 0 (b) 0.1 (c) 0.5
(d) 1.0 (e) 10.0

Mathew Botros

Montclair State University

Problem 12

Draw four simple graphs, each with a range of phenotypes (e.g., height) on the $x$ -axis and numbers of individuals on the $y$ -axis. Each graph should illustrate one of the following: (a) no selection (b) stabilizing selection (c) directional selection (d) disruptive selection.

Josee Pacheco

Numerade Educator

Problem 13

Given that mutations are almost always neutral or harmful, why are mutations nevertheless essential to evolution? Explain your answer.

Mathew Botros

Montclair State University

Problem 14

Explain this apparent paradox:
Scientists discuss evolution in terms of genotype fitness (the selective advantage that a particular genotype confers on an individual), yet natural selection acts on an organism's phenotype.

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 15

Why is it easier for researchers to study the genetic contribution to disease in the population of Finland or Iceland as opposed to that of the United States?

Mathew Botros

Montclair State University

Problem 16

Evolution is sometimes characterized as "survival of the fittest." Is this wording consistent with an evolutionary biologist's definitions of fitness and natural selection? Is it a good way to think about evolution or a poor one?

Mathew Botros

Montclair State University

Problem 17

The recessive allele that causes Ellis-van Creveld syndrome when homozygous has a frequency of about 0.07 in the Amish population of Pennsylvania, although its frequency is only about 0.001 in the general population. How many persons out of one thousand in the Amish population would be expected to have the disease? How many out of one million in the general population?

Morgan Thompson

Morgan Thompson

Numerade Educator

Problem 18

You study males in populations of a certain species of minnows in a series of lakes at different latitudes. You find that they exhibit clinal variation in average weight at maturity and hypothesize that the weight differences are due to genetic factors. What might you predict about the average weights at maturity of representatives of each popu|ation reared in aquaria if your hypothesis is correct?

Josee Pacheco

Numerade Educator

Problem 19

Automated techniques are providing new information on the extent of genetic polymorphism among humans, particularly with respect to single nucleotide polymorphisms (SNPs) and copy number variations $(\mathrm{CNVs}) .$ In what ways might this information prove useful? In what ways might it present challenges?

Josee Pacheco

Numerade Educator