Deck 24: Evolutionary Genetics

Question 1

Which publication by Charles Darwin outlines his theory for evolution?

A) The Origin of Evolution
B) The Origin of the Galapagos
C) The Origin of Species
D) Voyage to the Galapagos
E) The Beagle's Voyage

Answer 1

C

Question 2

According to Darwin's theory of natural selection:
1)Individuals within a species vary with regards to heritable traits.
2)Individuals who have certain characteristics are more able to survive and reproduce.
3)Individuals who pass their traits down to offspring will eventually change the characteristics of the species.

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Answer 2

E

Question 3

Which structure was examined by Dobzhansky and his collaborators,enabling the detection of variability underlying a phenotype?

A) Polytene chromosomes in Drosophila
B) Polytene chromosomes in C. elegans
C) Plasmids in E. coli
D) Transposons in humans
E) None of these

Answer 3

A

Question 4

In the study of polytene chromosomes among Drosophila it was determined that:
1)Different arrangements predominated different geographical regions.
2)Frequencies of the arrangements changed seasonally.
3)Long-term changes in the frequencies of arrangements occur in some populations.

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 5

Proteins that exhibit electrophoretic variation with at least two of the variants having frequencies greater than 1 percent in the population are known as

A) polymorphic
B) monomorphic
C) amorphic
D) aneuplodic
E) None of these

Question 6

What did Darwin propose to be the driving force of evolution in nature?

A) Selection
B) Migration
C) Emigration
D) Inbreeding
E) Random mating

Question 7

Which of the following is not considered a polymorphism?

A) Light and dark forms of Peppered moths
B) White or blue flowered Lianthus parryae
C) Blood types
D) White eyes in Drosophila
E) All of these

Question 8

Darwin proposed that a species changes as a result of

A) generations of malnutrition.
B) generations of competition among individuals.
C) lack of intelligence.
D) genetic abnormalities.
E) None of these

Question 9

Who is credited with proposing the original theory of evolution?

A) Charles Darwin
B) James Watson
C) Francis Crick
D) Alfred Wallace
E) None of these

Question 10

The status of the Duffy polymorphism for blood type varies among

A) individual members of the same family.
B) human ethnic groups.
C) human religious groups.
D) inbred family groups.
E) None of these

Question 11

Which of the following would be the best example of polymorphisms changing in various environments?

A) Yellow eyes and white wings in Drosophila
B) The Duffy polymorphism in humans
C) The light and dark forms of the Peppered moth
D) The white and blue flowers of Lianthus parryae
E) All of these

Question 12

Different forms of an enzyme encoded by different alleles of a gene are known as

A) isoalleles.
B) isoenzymes.
C) allozymes.
D) alloleles.
E) isozymes.

Question 13

Different colored bands on the shells of land snails would be classified as what type of variation?

A) Molecular variation
B) Chromosomal variation
C) Phenotypic variation
D) Molecular variation and chromosomal variation
E) Chromosomal variation and phenotypic variation

Question 14

Allozymes differ from each other by

A) one amino acid in their central sequence.
B) one or more amino acids in their overall sequences.
C) less than one amino acid in their central sequences.
D) the tertiary structure.
E) None of these

Question 15

Which of the following principles grounded Darwin's work and allowed for an explanation of how variations are inherited?
1)Wallace's theory of inheritance
2)Mendel's principles of inheritance
3)Morgan's principles of inheritance

A) 1
B) 2
C) 3
D) 1 and 2
E) 1 and 3

Question 16

What type of mutation created the different arrangements of banding patterns in the polytene chromosomes studied by Dobzhansky?

A) Transversion
B) Transition
C) Inversion
D) Point mutation
E) Frameshift mutation

Question 17

Which type of variation was first to be analyzed by naturalists and geneticists?

A) Molecular variation
B) Chromosomal variation
C) Phenotypic variation
D) Molecular variation and chromosomal variation
E) Chromosomal variation and phenotypic variation

Question 18

In the study of polytene chromosomes among Drosophila it was determined that __________ selection plays an important role in maintaining chromosomal polymorphisms in nature. A)Artificial selection
B)Balancing selection
C)Disruptive selection
D)Dispersive selection
E)None of these

Question 19

Which of the following were not explained in Darwin's theory of evolution?
1)The origin of variation among individuals
2)How particular variants are inherited
3)How individuals are selected in nature to pass on their traits

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 20

Which of the following is a disadvantage of protein gel electrophoresis?
1)Nonsoluble,hydrophobic proteins cannot readily be analyzed.
2)It focuses on gene products rather than on the genes themselves.
3)It tells nothing about variation in the nongenic portion of a genome.

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 21

Evolutionary relationships among organisms are summarized in diagrams called

A) pedigree charts.
B) phylogenetic trees.
C) family trees.
D) pedigree charts and phylogenetic trees.
E) pedigree charts and family trees.

Question 22

Which type of evidence was used by Darwin to propose that species evolve?

A) DNA
B) Protein structure
C) Nucleotide sequence
D) Fossils
E) All of these

Question 23

The molecular source of variation that underlies the process of evolution is

A) mutation
B) genetic drift
C) artificial selection
D) migration
E) emigration

Question 24

Which of the following is not an advantage of studying evolution through the use of DNA and proteins?

A) DNA and protein sequences follow simple rules of heredity.
B) Molecular sequence data are easy to obtain.
C) Molecular sequence data are amenable to quantitative analyses framed in the context of evolutionary genetics theory.
D) Researchers usually cannot obtain DNA or protein sequence data from extinct organisms.
E) Molecular sequence data allow researchers to investigate evolutionary relationships among organisms that are phenotypically very dissimilar.

Question 25

Which type of molecular sequence would is best for constructing a phylogenetic tree?

A) Homologous
B) Heterologous
C) Analogous
D) Heterozygous
E) Homozygous

Question 26

Which of the following can be shown using a phylogenetic tree?
1)Relationships among organisms
2)How each organism in the tree evolved over time
3)Chromosomal makeup of each organism

A) 1
B) 2
C) 3
D) 1 and 2
E) 1 and 3

Question 27

Each bifurcation in a phylogenetic tree represents

A) a different ancestor.
B) a common ancestor.
C) a common descendent.
D) a different descendent.
E) a mutation

Question 28

Two molecular sequences that come to resemble each other even though they are derived from entirely different ancestral sequences are said to be

A) homologous.
B) heterologous.
C) analogous.
D) heterozygous.
E) homozygous.

Question 29

Nucelotide differences that have no effect on the amino acid sequence of the polypeptide are known as

A) null polymorphisms.
B) lethal polymorphisms.
C) isopolymorphisms.
D) silent polymorphisms.
E) missense polymorphisms.

Question 30

Polymorphisms in DNA structure have been detected by

A) sequencing cloned DNA.
B) sequencing PCR amplified DNA.
C) diagnostic gene chips.
D) sequencing cloned DNA and Sequencing PCR amplified DNA.
E) All of these

Question 31

In The Origin of Species,Darwin repeatedly referred to evolution as a process of

A) descent with variation.
B) descent with modification.
C) descent with change.
D) descent of speciation.
E) None of these

Question 32

Which of the following is considered a "document of evolutionary history" today?

A) Fossils
B) DNA
C) Proteins
D) Fossils and DNA
E) All of these

Question 33

How can the rate of evolution be determined using a phylogenetic tree?
1)Link the branch points of a tree to specific times in the evolutionary history of the sequences
2)Link the common ancestor to a specific evolutionary era in history
3)Link the analogous sequences to specific times in evolutionary history

A) 1
B) 2
C) 3
D) 1 and 2
E) None of these

Question 34

Even if they have diverged significantly from the ancestor and are different from each other descendants of an ancestral DNA or protein sequence are said to be

A) homologous.
B) heterologous.
C) analogous.
D) heterozygous.
E) homozygous.

Question 35

How are silent polymorphisms possible?
1)The degeneracy of the genetic code
2)The commaless nature of the genetic code
3)The high rate of mutations in species

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 36

The best phylogenetic tree is one that requires the fewest mutational changes to explain the evolution of all the tree's sequences from a common ancestor.This is known as

A) the principle of partrology.
B) the principle of topology.
C) the principle of parsimony.
D) the principle of topography.
E) the principle of homology.

Question 37

Which type of DNA sequence exhibits the highest evolutionary rates?

A) Nucleotides in the second position of a codon
B) Nucleotides in the first position of a codon
C) Pseudogenes
D) Introns
E) Rates among DNA sequences do not vary

Question 38

A distinct basic structure in a phylogenetic tree is known as

A) heterology.
B) topography.
C) topology.
D) parsimony.
E) homology.

Question 39

Which sequence was used to determine an evolutionary rate?

A) a-globin
B) Cro
C) RecA
D) a-globin and RecA
E) All of these

Question 40

Which of the following is not a common feature shared by the methods used to construct a phylogenetic tree?

A) Aligning the sequences to allow comparisons among them
B) Ascertaining the amount of similarity (or difference) between any two sequences
C) Grouping the sequences on the basis of similarity
D) Placing the sequences at the tips of a tree
E) Placing a chromosome map at the base of each tree

Question 41

The process whereby subpopulations evolve reproductive isolation while they are geographically separated is called

A) allopatric speciation.
B) sympatric speciation.
C) synonymous speciation.
D) analogous speciation.
E) homologous speciation.

Question 42

In evolutionary genetics a group of populations that share a common gene pool is known as a/an

A) class.
B) order.
C) genus.
D) species.
E) family.

Question 43

Briefly explain the procedure of gel electrophoresis and how proteins can be separated and studied using this procedure.

Question 44

Briefly explain the various forms of DNA technologies and how they are used to study genetic variability in various species.

Question 45

What can be can be determined by calculating the average number of amino acid or nucleotide changes that have occurred per site in a molecule since two or more evolving lineages diverged from a common ancestor?
1)The amount of phenotypic evolution
2)The rate of molecular evolution
3)The future of phenotypic evolution

A) 1
B) 2
C) 3
D) 1 and 3
E) All of these

Question 46

The process of evolving reproductive isolation between subpopulations that exist in the same territory is called

A) allopatric speciation.
B) sympatric speciation.
C) synonymous speciation.
D) analogous speciation.
E) homologous speciation.

Question 47

Fossil evidence indicates that the remote ancestors of human beings evolved in Africa,beginning about

A) 3,000 years ago.
B) 50,000-100,000 years ago.
C) 4-5 million years ago.
D) 100 million years ago.
E) 60,000 years ago.

Question 48

What are the advantages of studying evolution using DNA and protein sequences as compared to more traditional methods such as comparative anatomy and physiology?

Question 49

Genetic evidence indicates that modern human populations may have emerged from Africa and subsequently spread to other continents how many years ago?

A) 50,000-100,000 years ago
B) 100,000-200,000 years ago
C) 4-5 million years ago
D) 100 million years ago
E) 60,000 years ago

Question 50

A researcher has sequenced a gene from four populations of an organism,denoted 1,2,3,and 4.This gene consists of two exons separated by an intron; a 5¢ untranslated region (UTR)is included in the first exon,and a 3¢ UTR is included in the second exon.When we align the four sequences of this gene,we find that two of them have a transposable element insertion in the 3¢ UTR,and three of them have lost a short sequence within the intron.We also see that each of the four sequences has at least one feature that uniquely distinguishes it from all the other sequences-a G:C base pair near the start of the coding sequence in exon I in sequence 1,an A:T base pair near the start of exon II in sequence 2,a C:G base pair in the 5¢ UTR and a T:A base pair near the end of the coding sequence in exon II in sequence 3,and an A:T base pair in the 5¢ UTR,a C:G base pair in the middle of exon II,and a G:C base pair in the 3¢ UTR in sequence 4.Based on these similarities and differences,draw a phylogenetic tree to show how the four sequences are related.

Question 51

The Neutral Theory states that:
1)For selectively neutral mutations,the rate of molecular evolution is equal to the rate at which these mutations occur in the population.
2)The rate of evolution does not depend on population size,the efficiency of selection,or peculiarities of the mating system.
3)If the neutral mutation rate is constant,then nucleotide and amino acid substitutions,which are due to mutations,should occur in clocklike fashion in all evolving lineages.

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 52

How do geneticists explain the variation in evolution rates?

Question 53

Which of the following is a key event in the speciation process?
1)Artificial selection
2)Genetic drift
3)Development of reproductive isolation between populations

A) 1
B) 2
C) 3
D) 1 and 2
E) 1 and 3