Question 1

Multigene families are

Accepted Answer

A) groups of enhancers that control transcription. 
B) usually clustered at the telomeres. 
C) equivalent to the operons of prokaryotes. 
D) sets of genes that are coordinately controlled. 
E) identical or similar genes that have evolved by gene duplication. 
A) groups of enhancers that control transcription. 
B) usually clustered at the telomeres. 
C) equivalent to the operons of prokaryotes. 
D) sets of genes that are coordinately controlled. 
E) identical or similar genes that have evolved by gene duplication.

Question 2

What is the most probable explanation for the continued presence of pseudogenes in a genome such as our own?

Accepted Answer

A) They are genes that had a function at one time, but that have lost their function because they have been translocated to a new location. 
B) They are genes that have accumulated mutations to such a degree that they would code for different functional products if activated. 
C) They are duplicates or near duplicates of functional genes but cannot function because they would provide inappropriate dosage of protein products. 
D) They are genes with significant inverted sequences. 
E) They are genes that are not expressed, even though they have nearly identical sequences to expressed genes. 
A) They are genes that had a function at one time, but that have lost their function because they have been translocated to a new location. 
B) They are genes that have accumulated mutations to such a degree that they would code for different functional products if activated. 
C) They are duplicates or near duplicates of functional genes but cannot function because they would provide inappropriate dosage of protein products. 
D) They are genes with significant inverted sequences. 
E) They are genes that are not expressed, even though they have nearly identical sequences to expressed genes.

Question 3

In order to determine the probable function of a particular sequence of DNA in humans, what might be the most reasonable approach?

Accepted Answer

A) Prepare a knockout mouse without a copy of this sequence and examine the mouse phenotype. 
B) Genetically engineer a mouse with a copy of this sequence and examine its phenotype. 
C) Look for a reasonably identical sequence in another species, prepare a knockout of this sequence in that species and look for the consequences. 
D) Prepare a genetically engineered bacterial culture with the sequence inserted and assess which new protein is synthesized. 
E) Mate two individuals heterozygous for the normal and mutated sequences. 
A) Prepare a knockout mouse without a copy of this sequence and examine the mouse phenotype. 
B) Genetically engineer a mouse with a copy of this sequence and examine its phenotype. 
C) Look for a reasonably identical sequence in another species, prepare a knockout of this sequence in that species and look for the consequences. 
D) Prepare a genetically engineered bacterial culture with the sequence inserted and assess which new protein is synthesized. 
E) Mate two individuals heterozygous for the normal and mutated sequences.

Question 4

In comparing the genomes of humans and those of other higher primates, it is seen that humans have a large metacentric pair we call chromosome #2 among our 46 chromosomes, while the other primates of this group have 48 chromosomes and any pair like the human #2 pair is not present; instead the primate groups each have two pairs of midsize acrocentric chromosomes. What is the most likely explanation?

Accepted Answer

A) The ancestral organism had 48 chromosomes and at some point a centric fusion event occurred and provided some selective advantage. 
B) The ancestral organism had 46 chromosomes, but primates evolved when one of the pairs broke in half. 
C) At some point in evolution, human ancestors and primate ancestors were able to mate and produce fertile offspring, making a new species. 
D) Chromosome breakage results in additional centromeres being made in order for meiosis to proceed successfully. 
E) Transposable elements transferred significantly large segments of the chromosomes to new locations. 
A) The ancestral organism had 48 chromosomes and at some point a centric fusion event occurred and provided some selective advantage. 
B) The ancestral organism had 46 chromosomes, but primates evolved when one of the pairs broke in half. 
C) At some point in evolution, human ancestors and primate ancestors were able to mate and produce fertile offspring, making a new species. 
D) Chromosome breakage results in additional centromeres being made in order for meiosis to proceed successfully. 
E) Transposable elements transferred significantly large segments of the chromosomes to new locations.

Question 5

Which of the following is a major distinction between a transposon and a retrotransposon?

Accepted Answer

A) A transposon always leaves a copy of itself at its original position and a retrotransposon does not. 
B) A retrotransposon always uses the copy-paste mechanism, while a transposon uses cut and paste mechanism. 
C) A transposon is related to a virus and a retrotransposon is not. 
D) A transposon moves via a DNA intermediate and a retrotransposon via an RNA intermediate. 
E) The positioning of a transposon copy is transient while that of a retrotransposon is permanent. 
A) A transposon always leaves a copy of itself at its original position and a retrotransposon does not. 
B) A retrotransposon always uses the copy-paste mechanism, while a transposon uses cut and paste mechanism. 
C) A transposon is related to a virus and a retrotransposon is not. 
D) A transposon moves via a DNA intermediate and a retrotransposon via an RNA intermediate. 
E) The positioning of a transposon copy is transient while that of a retrotransposon is permanent.

Question 6

How might identical and obviously duplicated gene sequences have gotten from one chromosome to another?

Accepted Answer

A) by normal meiotic recombination 
B) by normal mitotic recombination between sister chromatids 
C) by transcription followed by recombination 
D) by chromosomal translocation 
E) by deletion followed by insertion 
A) by normal meiotic recombination 
B) by normal mitotic recombination between sister chromatids 
C) by transcription followed by recombination 
D) by chromosomal translocation 
E) by deletion followed by insertion

Question 7

Alu elements account for about 10% of the human genome. What does this mean?

Accepted Answer

A) Alu elements cannot be transcribed into RNA. 
B) Alu elements evolved in very ancient times, before mammalian radiation. 
C) Alu elements represent the result of transposition. 
D) No Alu elements are found within individual genes. 
E) Alu elements are cDNA and therefore related to retrotransposons. 
A) Alu elements cannot be transcribed into RNA. 
B) Alu elements evolved in very ancient times, before mammalian radiation. 
C) Alu elements represent the result of transposition. 
D) No Alu elements are found within individual genes. 
E) Alu elements are cDNA and therefore related to retrotransposons.

Question 8

When does exon shuffling occur?

Accepted Answer

A) during splicing of DNA 
B) during mitotic recombination 
C) as an alternative splicing pattern in post-transcriptional processing 
D) as an alternative cleavage or modification post-translationally 
E) as the result of faulty DNA repair 
A) during splicing of DNA 
B) during mitotic recombination 
C) as an alternative splicing pattern in post-transcriptional processing 
D) as an alternative cleavage or modification post-translationally 
E) as the result of faulty DNA repair

Question 9

Bioinformatics can be used to scan sequences for probable genes looking for start and stop sites for transcription and for translation, for probable splice sites, and for sequences known to be found in other known genes. Such sequences containing these elements are called

Accepted Answer

A) expressed sequence tags. 
B) cDNA. 
C) multigene families. 
D) proteomes. 
E) short tandem repeats. 
A) expressed sequence tags. 
B) cDNA. 
C) multigene families. 
D) proteomes. 
E) short tandem repeats.

Question 10

Several of the different globin genes are expressed in humans, but at different times in development. What mechanism could allow for this?

Accepted Answer

A) exon shuffling 
B) intron activation 
C) pseudogene activation 
D) differential translation of mRNAs 
E) differential gene regulation over time 
A) exon shuffling 
B) intron activation 
C) pseudogene activation 
D) differential translation of mRNAs 
E) differential gene regulation over time

Question 11

Fragments of DNA have been extracted from the remnants of extinct wooly mammoths, amplified, and sequenced. These can now be used to

Accepted Answer

A) introduce into relatives, such as elephants, certain mammoth traits. 
B) clone live wooly mammoths. 
C) study the relationships among wooly mammoths and other wool-producers. 
D) understand the evolutionary relationships among members of related taxa. 
E) appreciate the reasons why mammoths went extinct 
A) introduce into relatives, such as elephants, certain mammoth traits. 
B) clone live wooly mammoths. 
C) study the relationships among wooly mammoths and other wool-producers. 
D) understand the evolutionary relationships among members of related taxa. 
E) appreciate the reasons why mammoths went extinct

Question 12

What is it about short tandem repeat DNA that makes it useful for DNA fingerprinting?

Accepted Answer

A) The number of repeats varies widely from person to person or animal to animal. 
B) The sequence of DNA that is repeated varies significantly from individual to individual. 
C) The sequence variation is acted upon differently by natural selection in different environments. 
D) Every racial and ethnic group has inherited different short tandem repeats. 
A) The number of repeats varies widely from person to person or animal to animal. 
B) The sequence of DNA that is repeated varies significantly from individual to individual. 
C) The sequence variation is acted upon differently by natural selection in different environments. 
D) Every racial and ethnic group has inherited different short tandem repeats.

Question 13

For mapping studies of genomes, most of which were far along before 2000, the 3-stage method was often used. Which is the usual order in which the stages were performed, assuming some overlap of the three?

Accepted Answer

A) genetic map, sequencing of fragments, physical map 
B) linkage map, physical map, sequencing of fragments 
C) sequencing of entire genome, physical map, genetic map 
D) cytogenetic linkage, sequencing, physical map 
E) physical map, linkage map, sequencing 
A) genetic map, sequencing of fragments, physical map 
B) linkage map, physical map, sequencing of fragments 
C) sequencing of entire genome, physical map, genetic map 
D) cytogenetic linkage, sequencing, physical map 
E) physical map, linkage map, sequencing

Question 14

Unequal crossing over during Prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of hemoglobin, known as hemoglobin Lepore, is known in the human population. Hemoglobin Lepore has a deleted set of amino acids. If it was caused by unequal crossing over, what would be an expected consequence?

Accepted Answer

A) If it is still maintained in the human population, hemoglobin Lepore must be selected for in evolution. 
B) There should also be persons born with, if not living long lives with, an anti-Lepore mutation or duplication. 
C) Each of the genes in the hemoglobin gene family must show the same deletion. 
D) The deleted gene must have undergone exon shuffling 
E) The deleted region must be located in a different area of the individual's genome. 
A) If it is still maintained in the human population, hemoglobin Lepore must be selected for in evolution. 
B) There should also be persons born with, if not living long lives with, an anti-Lepore mutation or duplication. 
C) Each of the genes in the hemoglobin gene family must show the same deletion. 
D) The deleted gene must have undergone exon shuffling 
E) The deleted region must be located in a different area of the individual's genome.

Question 15

Which of the following is a representation of gene density?

Accepted Answer

A) Humans have 2,900 Mb per genome. 
B) C. elegans has ~20,000 genes. 
C) Humans have ~25,000 genes in 2,900 Mb. 
D) Humans have 27,000 bp in introns. 
E) Fritillaria has a genome 40 times the size of a human. 
A) Humans have 2,900 Mb per genome. 
B) C. elegans has ~20,000 genes. 
C) Humans have ~25,000 genes in 2,900 Mb. 
D) Humans have 27,000 bp in introns. 
E) Fritillaria has a genome 40 times the size of a human.

Question 16

Homeotic genes

Accepted Answer

A) encode transcription factors that control the expression of genes responsible for specific anatomical structures. 
B) are found only in Drosophila and other arthropods. 
C) are the only genes that contain the homeobox domain. 
D) encode proteins that form anatomical structures in the fly. 
E) are responsible for patterning during plant development. 
A) encode transcription factors that control the expression of genes responsible for specific anatomical structures. 
B) are found only in Drosophila and other arthropods. 
C) are the only genes that contain the homeobox domain. 
D) encode proteins that form anatomical structures in the fly. 
E) are responsible for patterning during plant development.

Question 17

Bioinformatics includes all of the following except

Accepted Answer

A) using computer programs to align DNA sequences. 
B) analyzing protein interactions in a species. 
C) using molecular biology to provide biological information to a system so that it gets expressed. 
D) development of computer-based tools for genome analysis. 
E) use of mathematical tools to make sense of biological systems. 
A) using computer programs to align DNA sequences. 
B) analyzing protein interactions in a species. 
C) using molecular biology to provide biological information to a system so that it gets expressed. 
D) development of computer-based tools for genome analysis. 
E) use of mathematical tools to make sense of biological systems.

Exam 21: Genomes and Their Evolution

Multigene families are

What is the most probable explanation for the continued presence of pseudogenes in a genome such as our own?

In order to determine the probable function of a particular sequence of DNA in humans, what might be the most reasonable approach?

Which of the following is a major distinction between a transposon and a retrotransposon?

How might identical and obviously duplicated gene sequences have gotten from one chromosome to another?

Alu elements account for about 10% of the human genome. What does this mean?

When does exon shuffling occur?

Bioinformatics can be used to scan sequences for probable genes looking for start and stop sites for transcription and for translation, for probable splice sites, and for sequences known to be found in other known genes. Such sequences containing these elements are called

Several of the different globin genes are expressed in humans, but at different times in development. What mechanism could allow for this?

Fragments of DNA have been extracted from the remnants of extinct wooly mammoths, amplified, and sequenced. These can now be used to

What is it about short tandem repeat DNA that makes it useful for DNA fingerprinting?

For mapping studies of genomes, most of which were far along before 2000, the 3-stage method was often used. Which is the usual order in which the stages were performed, assuming some overlap of the three?

Which of the following is a representation of gene density?

Homeotic genes

Bioinformatics includes all of the following except

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Control of Gene Expression

Viruses

Biotechnology

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems

Conservation Biology and Restoration Ecology

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