Question 1

Natural selection occurs when

Accepted Answer

A)  individuals whose phenotypes are best suited for environmental conditions have higher reproductive success and contribute more alleles to the next generation. 
B)  humans breed certain individuals with the most desirable phenotypes. 
C)  individuals whose phenotypes are best suited for environmental conditions have lower reproductive success but live longer. 
D)  the genotype of an individual does not determine whether or not is has reproductive success. 
A)  individuals whose phenotypes are best suited for environmental conditions have higher reproductive success and contribute more alleles to the next generation. 
B)  humans breed certain individuals with the most desirable phenotypes. 
C)  individuals whose phenotypes are best suited for environmental conditions have lower reproductive success but live longer. 
D)  the genotype of an individual does not determine whether or not is has reproductive success.

Question 2

Microevolution is defined as

Accepted Answer

A)  changes in the gene pool from one generation to the next. 
B)  changes in gene flow from one generation to the next. 
C)  the ability of different genotypes to succeed in a particular environment. 
D)  morphological changes that occur from one generation to the next. 
A)  changes in the gene pool from one generation to the next. 
B)  changes in gene flow from one generation to the next. 
C)  the ability of different genotypes to succeed in a particular environment. 
D)  morphological changes that occur from one generation to the next.

Question 3

How does inbreeding affect the Hardy-Weinberg equilibrium?

Accepted Answer

A)  It makes it more likely for the population to remain in Hardy-Weinberg equilibrium. 
B)  It has no effect on the Hardy-Weinberg equilibrium. 
C)  It results in a higher level of either dominant or recessive homozygotes. 
D)  It results in a higher level of heterozygotes. 
A)  It makes it more likely for the population to remain in Hardy-Weinberg equilibrium. 
B)  It has no effect on the Hardy-Weinberg equilibrium. 
C)  It results in a higher level of either dominant or recessive homozygotes. 
D)  It results in a higher level of heterozygotes.

Question 4

A natural disaster that resulted in the loss of genetic diversity in a population would be an example of a

Accepted Answer

A)  founder effect. 
B)  genetic drift. 
C)  bottleneck effect. 
D)  natural selection. 
A)  founder effect. 
B)  genetic drift. 
C)  bottleneck effect. 
D)  natural selection.

Question 5

Horizontal gene transfer occurs

Accepted Answer

A)  within and between species of eukaryotes and prokaryotes. 
B)  between prokaryotic species only. 
C)  between eukaryotic species only. 
D)  only from prokaryotes to eukaryotes. 
A)  within and between species of eukaryotes and prokaryotes. 
B)  between prokaryotic species only. 
C)  between eukaryotic species only. 
D)  only from prokaryotes to eukaryotes.

Question 6

Migration of a random few individuals from one population to a new area to establish a new population is an example of

Accepted Answer

A)  bottleneck effect. 
B)  mutation. 
C)  founder effect. 
D)  selection. 
A)  bottleneck effect. 
B)  mutation. 
C)  founder effect. 
D)  selection.

Question 7

If in a population the rate of mutation that converts the A allele to the a allele is 10⁻⁶ and the current frequency of the A allele is 0.75 and the a allele is 0.25,then the frequency of the A and a alleles in the next generation will be

Accepted Answer

A)  A: 0.75
A: 0.25 
B)  A: 0.7499993
A: 0.2500007 
C)  A: 0.750007
A: 0.2499993 
D)  A: 0.74
A: 0.26 
A)  A: 0.75
A: 0.25 
B)  A: 0.7499993
A: 0.2500007 
C)  A: 0.750007
A: 0.2499993 
D)  A: 0.74
A: 0.26

Question 8

Match between columns
                        Premises: Exons of preexisting genes are rearranged to make a new combination
Genes from one species introduced into another species
Recombination to produce new combinations of alleles
Increase or decrease in the number of repetitive sequences
Production of hybrid offspring
Independent segregation of different homologous chromosomes gives rise to new combinations of alleles
Chromosome structure changed by deletion, duplications, inversions, translocations or there is a change in ploidy
Conjugation, transduction and transformation
Point mutations, small deletions and insertions
Additional copies of a gene occur through misaligned crossing over

Accepted Answer

The Answer of interspecies crosses and gene duplications and horizontal is...

Question 9

The probability that two alleles will be identical for a given gene in an individual because the alleles are from the same ancestor is estimated by

Accepted Answer

A)  the calculation of average heterozygosity. 
B)  the Hardy-Weinberg equation. 
C)  the inbreeding coefficient. 
D)  the chi-square test. 
A)  the calculation of average heterozygosity. 
B)  the Hardy-Weinberg equation. 
C)  the inbreeding coefficient. 
D)  the chi-square test.

Question 10

At equilibrium the allelic and genotypic frequencies of a population change over time.

Accepted Answer

A) True 
 B)False

Question 11

You are preparing to perform DNA fingerprinting by PCR for the first time.Select the reagent that would result in complications in the interpretation of your results.

Accepted Answer

A)  PCR primers that anneal to the repetitive region of the microsatellites 
B)  PCR primers that anneal to regions flanking the microsatellites 
C)  Human DNA 
D)  Taq polymerase 
A)  PCR primers that anneal to the repetitive region of the microsatellites 
B)  PCR primers that anneal to regions flanking the microsatellites 
C)  Human DNA 
D)  Taq polymerase

Question 12

Which of the following types of selection creates two phenotypic classes from a single original distribution?

Accepted Answer

A)  disruptive selection 
B)  stabilizing selection 
C)  directional selection 
D)  balancing selection 
A)  disruptive selection 
B)  stabilizing selection 
C)  directional selection 
D)  balancing selection

Question 13

If the allele frequency of the dominant allele is 0.4,what value is used for the term p² in the equation p² + 2pq + q² = 1?

Accepted Answer

A)  0.4 
B)  0.2 
C)  0.16 
D)  16 
A)  0.4 
B)  0.2 
C)  0.16 
D)  16

Question 14

The mechanism that results in a change in allele frequencies due to random processes is known as

Accepted Answer

A)  genetic drift. 
B)  natural selection. 
C)  migration. 
D)  nonrandom mating. 
A)  genetic drift. 
B)  natural selection. 
C)  migration. 
D)  nonrandom mating.

Question 15

In a given population of Drosophila,curly wings (c )is recessive to the wild-type condition of straight wings (c⁺ ).You isolate a population of 35 curly winged flies,70 flies that are heterozygous for straight wings,and 45 that are homozygous for straight wings.What is the total number of alleles in the gene pool?

Accepted Answer

A)  2 
B)  150 
C)  230 
D)  300 
E)  None of these choices are correct 
A)  2 
B)  150 
C)  230 
D)  300 
E)  None of these choices are correct

Question 16

If a gene has more than one allele and each allele has a frequency that is less than 99%,then the gene is considered to be

Accepted Answer

A)  monomorphic. 
B)  polymorphic. 
C)  bialleleic. 
D)  polyallelic. 
A)  monomorphic. 
B)  polymorphic. 
C)  bialleleic. 
D)  polyallelic.

Question 17

Select the definition of genetic drift.

Accepted Answer

A)  Changes in allele frequencies in a population due to random fluctuations 
B)  Changes in allele frequencies in a population due to migration 
C)  Changes in genotype frequencies in a population due to new mutations 
D)  Changes in genome size in a species due to random mutations 
A)  Changes in allele frequencies in a population due to random fluctuations 
B)  Changes in allele frequencies in a population due to migration 
C)  Changes in genotype frequencies in a population due to new mutations 
D)  Changes in genome size in a species due to random mutations

Question 18

In a given population of Drosophila,curly wings (c )is recessive to the wild-type condition of straight wings (c⁺ ).You isolate a population of 35 curly winged flies,70 flies that are heterozygous for straight wings,and 45 that are homozygous for straight wings.What is the frequency of alleles in this population?

Accepted Answer

A)  35% c; 45% c⁺ 
B)  46.7% c; 53.3% c⁺ 
C)  50% c; 50% c⁺ 
D)  55% c; 45% c⁺ 
E)  None of these choices are correct. 
A)  35% c; 45% c⁺ 
B)  46.7% c; 53.3% c⁺ 
C)  50% c; 50% c⁺ 
D)  55% c; 45% c⁺ 
E)  None of these choices are correct.

Question 19

Which type of selection would lead to two distinct phenotypes?

Accepted Answer

A)  stabilizing selection 
B)  phenotype selection 
C)  fitness selection 
D)  disruptive selection 
E)  directional selection 
A)  stabilizing selection 
B)  phenotype selection 
C)  fitness selection 
D)  disruptive selection 
E)  directional selection

Question 20

Which of the following is NOT an assumption of the Hardy-Weinberg equation?

Accepted Answer

A)  There is no migration into or out of the population. 
B)  Individuals of the population mate randomly. 
C)  The population size is very large. 
D)  Selection favors the dominant allele. 
E)  There is no mutation occurring in the population. 
A)  There is no migration into or out of the population. 
B)  Individuals of the population mate randomly. 
C)  The population size is very large. 
D)  Selection favors the dominant allele. 
E)  There is no mutation occurring in the population.

Exam 23: Population Genetics

Natural selection occurs when

Microevolution is defined as

How does inbreeding affect the Hardy-Weinberg equilibrium?

A natural disaster that resulted in the loss of genetic diversity in a population would be an example of a

Horizontal gene transfer occurs

Migration of a random few individuals from one population to a new area to establish a new population is an example of

If in a population the rate of mutation that converts the A allele to the a allele is 10⁻⁶ and the current frequency of the A allele is 0.75 and the a allele is 0.25,then the frequency of the A and a alleles in the next generation will be

The probability that two alleles will be identical for a given gene in an individual because the alleles are from the same ancestor is estimated by

At equilibrium the allelic and genotypic frequencies of a population change over time.

You are preparing to perform DNA fingerprinting by PCR for the first time.Select the reagent that would result in complications in the interpretation of your results.

Which of the following types of selection creates two phenotypic classes from a single original distribution?

If the allele frequency of the dominant allele is 0.4,what value is used for the term p² in the equation p² + 2pq + q² = 1?

The mechanism that results in a change in allele frequencies due to random processes is known as

If a gene has more than one allele and each allele has a frequency that is less than 99%,then the gene is considered to be

Select the definition of genetic drift.

Which type of selection would lead to two distinct phenotypes?

Which of the following is NOT an assumption of the Hardy-Weinberg equation?

Overview of Genetics

Reproduction and Chromosome Transmission

Mendelian Inheritance

Sex Determination and Sex Chromosomes

Extensions of Mendelian Inheritance

Extranuclear Inheritance, Imprinting, and Maternal Effect

Genetic Linkage and Mapping in Eukaryotes

Variation in Chromosome Structure and Number

Genetics in Bacteria

Genetics of Viruses

Molecular Structure of DNA and RNA

Molecular Structure of Chromosomes and Transposition

Dna Replication and Recombination

Gene Transcription and RNA Modification

Translation of MRNA

Gene Regulation in Bacteria

Gene Regulation in Eukaryotes

Non-Coding Rnas

Gene Mutation and DNA Repair

Molecular Technologies

Genomics

Medical Genetics and Cancer

Quantitative Genetics

Filters