Question 1

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 were caused by unequal crossing over, what would be an expected consequence?
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.

Accepted Answer

If hemoglobin Lepore is caused by unequal crossing over resulting in a deletion, then there may also be individuals born with a duplication of the same region. These individuals may have a different form of mutated hemoglobin, referred to as anti-Lepore.

Question 2

When does exon shuffling occur?
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

Accepted Answer

Exon shuffling occurs as an alternative splicing pattern in post-transcriptional processing. This is the process by which introns are removed from pre-mRNA and exons are joined together to create mature mRNA. Exon shuffling involves the rearrangement of exons within a single gene or between different genes, resulting in different combinations of exons being included in the mature mRNA. This can create new functional proteins with novel properties.

Question 3

Which of the following studies would not likely be characterized as evo-devo?
A)the study of a particular species to see whether or not it has developmental regulation
B)a study of the assortment of homeotic genes in the zebra
C)a comparison of the functions of a particular homeotic gene among four species of reptiles
D)a study of the environmental pressures on developmental stages such as the tadpole
E)a fossil comparison of organisms from the Devonian era

Accepted Answer

The answer of Which of the following studies would not...

Question 4

What are genomic "hot spots"?
A)the locations that correspond to most genetic diseases
B)the areas of a genome that most often mutate due to environmental effects
C)the locations that most often correspond with chromosomal breakpoints
D)the locations that correspond to most genetic diseases and the locations that most often correspond with chromosomal breakpoints
E)the locations that correspond to most genetic diseases, the areas of a genome that most often mutate due to environmental effects, and the locations that most often correspond with chromosomal breakpoints

Accepted Answer

Genomic "hot spots" are regions in the genome that are particularly susceptible to various types of alterations, including mutations due to environmental effects, locations that correspond with chromosomal breakpoints, and areas associated with genetic diseases. These regions are more likely than others to undergo changes that can have significant biological consequences.

Question 5

A consortium of 25 Canadian scientists, led by Dr. Rudnicki at the University of Ottawa, is looking at gene expression in both ________ cells. This is important in understanding regenerative medicine.
A)embryonic and adult stem
B)muscle and nervous tissue
C)RNA and DNA in
D)differentiation and post-fertilized
E)transposable elements and heterochromatin

Accepted Answer

The sentence directly states that the scientists are looking at gene expression in both embryonic and adult stem cells. This is important in understanding regenerative medicine, as stem cells have the ability to differentiate into various types of cells and can potentially be used to regenerate damaged or diseased tissues. The other options are not mentioned in the sentence and are not relevant to the context of regenerative medicine.

Question 6

Researchers at the University of British Columbia are working on a way to analyze gene expression within a single cell as it differentiates. This is significant because
A)cDNA libraries could be made.
B)tissue identification would be easier.
C)RNA is needed to understand expression and probing a cell as it undergoes differentiation is impossible at this point.
D)DNA within a single cell is difficult to extract.
E)generation of totipotent adult stem cells would be possible.

Accepted Answer

Understanding gene expression during differentiation requires analysis of RNA, which is difficult to observe in a single cell as it differentiates. The researchers at the University of British Columbia are working on a way to analyze gene expression within a single cell as it differentiates, which would lead to insights into the molecular processes behind differentiation.

Question 7

A project initiated at the University of Guelph is attempting to catalogue the differences of a short sequence within the mitochondrial DNA in all animal species. This ________ should allow the quick identification of a species.
A)shotgun approach
B)DNA barcoding
C)microarray
D)genechip
E)STR DNA

Accepted Answer

The project described is using DNA barcoding, which involves cataloguing the differences in a short sequence of mitochondrial DNA for quick species identification. The other options mentioned (shotgun approach, microarray, genechip, and STR DNA) are unrelated to this specific project.

Question 8

Use the following figure to answer the next few questions.
  
Types of DNA sequences in the human genome.
The pie chart above represents the relative frequencies of the following in the human genome:
I. repetitive DNA unrelated to transposons
II. repetitive DNA that includes transposons
III. unique noncoding DNA
IV. introns and regulatory sequences
V. exons
-Which region includes Alu elements and LI sequences?
A)A
B)B
C)C
D)D
E)E

Accepted Answer

The answer of Use the following figure to answer the...

Question 9

Gene sequences that remain very similar over many species are said to be
A)the same.
B)noncoding regions.
C)highly conserved.
D)of the same family.
E)resistant to mutation.

Accepted Answer

Gene sequences that remain very similar over many species are said to be highly conserved. This is because they have remained functionally important throughout evolution and any changes in these sequences may have negative effects on the organism's survival. Noncoding regions, on the other hand, may have more variation between species since they may not be under as much selective pressure. While the terms "the same" and "of the same family" may be applicable in some cases, they do not adequately describe the concept of conservation of gene sequences. Finally, while some sequences may be resistant to mutation, this is not necessarily indicative of their conservation.

Question 10

Which of the following can be duplicated in a genome?
A)DNA sequences above a minimum size only
B)DNA sequences below a minimum size only
C)entire chromosomes only
D)entire sets of chromosomes only
E)sequences, chromosomes, or sets of chromosomes

Accepted Answer

Sequences, chromosomes, or sets of chromosomes can all be duplicated in a genome. For example, mutations and errors in DNA replication can result in the duplication of a particular DNA sequence. Alternatively, whole chromosomes or sets of chromosomes can be duplicated through various mechanisms such as errors in meiosis or chromosomal abnormalities.

Question 11

The α-globin and β-globin gene families are found on different chromosomes in humans. What is the suspected reason for this?
A)They evolved at different times.
B)There was a gene duplication event.
C)The α-globin originally coded for a different protein family.
D)Our ancestors didn't use the α-globin genes.
E)They were originally on the same chromosome but one set was moved via transposable elements.

Accepted Answer

The α-globin and β-globin gene families are found on different chromosomes in humans because they were originally on the same chromosome but one set was moved via transposable elements.

Question 12

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

Accepted Answer

Looking for a reasonably identical sequence in another species, preparing a knockout of this sequence in that species, and looking for the consequences is the most reasonable approach because it allows for the examination of the function of the sequence in a different organism where the function may be more easily observed or studied. This approach also avoids potential ethical issues that may be associated with genetically engineering animals or humans.

Question 13

Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for that domain of a protein that binds to DNA in a regulatory developmental process. Which of the following would you then expect?
A)that homeotic genes are selectively expressed over developmental time
B)that a homeobox-containing gene has to be a developmental regulator
C)that homeoboxes cannot be expressed in nonhomeotic genes
D)that all organisms must have homeotic genes
E)that all organisms must have homeobox-containing genes

Accepted Answer

The answer of Homeotic genes contain a homeobox sequence that...

Question 14

It took 13 years and multiple labs to complete the first sequencing of the human genome (from 1990-2003). In 2007, a lab could complete the task in four months. This dramatic change in time to completion is a result of
A)more importance being placed on it and thus more money being put into it.
B)the development of high throughput methods and equipment.
C)more scientists becoming interested in the subject.
D)there being an initial learning curve; now we are proficient at it.
E)repetition: once the first one was done, it was easier to repeat it.

Accepted Answer

The development of high throughput methods and equipment allowed for faster completion of the sequencing of the human genome. This technological advancement increased efficiency and decreased the time needed for completion. While increased funding and interest also may have played a role, the development of high throughput methods and equipment was the main driver of the decreased time to completion.

Question 15

A recent report has indicated several conclusions about comparisons of our genome with that of Neanderthals. This report concludes, in part, that, at some period in evolutionary history, there was an admixture of the two genomes. This is evidenced by
A)some Neanderthal sequences not found in humans.
B)a small number of modern H. sapiens with Neanderthal sequences.
C)Neanderthal Y chromosomes preserved in the modern population of males.
D)mitochondrial sequences common to both groups.

Accepted Answer

The report indicates that a small number of modern H. sapiens have Neanderthal sequences, which suggests an admixture of the two genomes at some point in evolutionary history.

Question 16

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, whereas the other primates of this group have 48 chromosomes and any pair like the human chromosome 2 pair is not present; instead, the primate groups each have two pairs of midsize acrocentric chromosomes. What is the most likely explanation?
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.

Accepted Answer

The presence of a large metacentric pair in humans and the absence of such a pair in other higher primates can be explained by a centric fusion event that occurred in the human lineage after it diverged from the lineage leading to other primates. This fusion likely did not have a negative impact on our ancestors and may have even provided some selective advantage, ultimately leading to the fixation of the fused chromosome in the human population.

Question 17

Use the following figure to answer the next few questions.
  
Types of DNA sequences in the human genome.
The pie chart above represents the relative frequencies of the following in the human genome:
I. repetitive DNA unrelated to transposons
II. repetitive DNA that includes transposons
III. unique noncoding DNA
IV. introns and regulatory sequences
V. exons
-Which region is occupied by exons only (V)?
A)A
B)B
C)C
D)D
E)E

Accepted Answer

The answer of Use the following figure to answer the...

Question 18

By the year 2012, ________ genomes had been completely sequenced.
A)1000
B)2500
C)2800
D)3800
E)5300

Accepted Answer

The answer of By the year 2012, ________ genomes had...

Question 19

What is the benefit of metagenomics?
A)A community assemblage can be determined through mass sequencing and each specific species does not have to be isolated and cultured.
B)High throughput sequencing allows for faster identification of the genome.
C)It allows for a systems approach to genomics, relating parts of the organism to other parts.
D)It combines bioinformatics with genomics to get a clearer picture.
E)Many labs can work on the same problem and place the information into a shared database.

Accepted Answer

Metagenomics allows researchers to study genetic material recovered directly from environmental samples, enabling the analysis of microbial communities without the need for isolation and culturing of individual species.

Question 20

The large common repository for genetic sequences hosted by NCBI is called
A)GenBank.
B)BLAST.
C)GenesRus.
D)Prodata.
E)TreeNoMix.

Accepted Answer

GenBank is the common repository for genetic sequences hosted by NCBI. BLAST is a search tool that can be used to search for sequences in GenBank, but it is not the repository itself. GenesRus, Prodata, and TreeNoMix are not real repositories or databases for genetic sequences.

Quiz 21: Genomes and Their Evolution

When does exon shuffling occur?

Which of the following studies would not likely be characterized as evo-devo?

What are genomic "hot spots"?

A consortium of 25 Canadian scientists, led by Dr. Rudnicki at the University of Ottawa, is looking at gene expression in both ________ cells. This is important in understanding regenerative medicine.

Researchers at the University of British Columbia are working on a way to analyze gene expression within a single cell as it differentiates. This is significant because

A project initiated at the University of Guelph is attempting to catalogue the differences of a short sequence within the mitochondrial DNA in all animal species. This ________ should allow the quick identification of a species.

Gene sequences that remain very similar over many species are said to be

Which of the following can be duplicated in a genome?

The α-globin and β-globin gene families are found on different chromosomes in humans. What is the suspected reason for this?

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

Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for that domain of a protein that binds to DNA in a regulatory developmental process. Which of the following would you then expect?

It took 13 years and multiple labs to complete the first sequencing of the human genome (from 1990-2003) . In 2007, a lab could complete the task in four months. This dramatic change in time to completion is a result of

A recent report has indicated several conclusions about comparisons of our genome with that of Neanderthals. This report concludes, in part, that, at some period in evolutionary history, there was an admixture of the two genomes. This is evidenced by

By the year 2012, ________ genomes had been completely sequenced.

What is the benefit of metagenomics?

The large common repository for genetic sequences hosted by NCBI is called