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?

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?

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?

Accepted Answer

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

Question 4

What are genomic "hot spots"?

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.

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

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.

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?

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

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?

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?

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?

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?

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

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

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?

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)?

Accepted Answer

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

Question 18

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

Accepted Answer

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

Question 19

What is the benefit of metagenomics?

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

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