Chapter 10—Genomics
MULTIPLE CHOICE
1. All of an organism’s genetic information is contained in its
a.
DNA profile.
b.
genome.
c.
mtDNA.
d.
proteins.
e.
exome.
2. Which of the following statements about the Human Genome Project is FALSE?
a.
The HGP creates maps of the genomes of humans and other organisms.
b.
The HGP aimed to find out how couples could selectively have male babies.
c.
One of the aims of the HGP was to compile a list of expressed genes and nonexpressed
genes.
d.
One of the aims of the HGP was to identify all the proteins encoded by genes and their
functions.
e.
The HGP aimed to determine the location of all genes on a map of the human genome.
3. Sequencing of the portion of the human genome that carries genes was completed in
a.
1995
b.
1997
c.
1999
d.
2001
e.
2003
4. Which of the following is true about a complete chromosome map as generated from the Human
Genome Project?
a.
A map shows the position of genes on a particular chromosome.
b.
A map shows the order of and distance between genes on a particular chromosome.
c.
A map shows where all the genes are located on each chromosome.
d.
A map is constructed after DNA is sequenced and analyzed.
e.
All of these describe a complete chromosome map.
5. The human genome contains about ____ billion nucleotides.
a.
1. 2
b.
2. 4
c.
3.2
d.
4.2
e.
6.4
Chapter 10 – Genomics
6. Which of the following statements about bioinformatics is FALSE?
a.
Bioinformatics involves the storage of DNA sequence information in web-based
databases.
b.
New software was created to help collect, sort, and analyze DNA data.
c.
Research tools were created to access genome sequences.
d.
Bioinformatics attempts to identify the possible functions of genes via analysis.
e.
Bioinformatics analyzes repetitive sequences to identify the location of genes.
7. The field of proteomics involves ____.
a.
the large-scale study noncoding DNA.
b.
the large-scale study of the structure and function of proteins.
c.
the analysis of transposons.
d.
the visualization of large amounts of DNA under the microscope.
e.
identifying the location of genes on chromosomes.
8. Which of the following statements is FALSE?
a.
The closer two genes are to each other the more likely they are to be inherited.
b.
Genes close together on the same chromosome are said to be linked.
c.
It is more difficult to map genes to individual autosomes than to the sex chromosomes.
d.
Humans have many genes that are not present in other organisms.
e.
The field of genomics compares genes and their proteins from different species.
9. Which of the following statements regarding crossing over is FALSE?
a.
Crossing over takes place during meiosis.
b.
Crossing over occurs a few times on any one pair of chromosomes.
c.
Crossing over occurs at a few specific sites on the chromosomes.
d.
Information from crossing over events can be used to develop linkage maps.
e.
The closer two genes are on a chromosome, the less likely there will be crossing over
between them.
10. The frequency of crossing over between two genes is dependent on the
a.
size of each gene.
b.
distance between the genes.
c.
number of mutations in each gene causing disease.
d.
genetic information coded in the genes.
e.
number of alleles of each gene.
11. Genes show linkage when they
a.
are inherited together.
b.
are found on different chromosomes.
c.
they code for the same protein.
d.
have been cloned.
e.
All of these are correct.
12. The distance between two genes on a linkage map represents
a.
the frequency of crossing over that occurs between the genes.
b.
the percentage of the DNA sequence between the two genes that has been published.
c.
the percentage of descendants that do not show both traits.
d.
the exact distance between the genes.
e.
the amount of recombinant DNA molecules produced in the laboratory using the two
genes.
13. If two genes show a low, but measurable, frequency of crossing over, this means that
a.
the genes are far apart.
b.
the two genes are close together.
c.
the genes are present on different chromosomes..
d.
the genes have mutated.
e.
there has been a mistake made by the researchers.
14. Two linked genes are separated by 25 cM. We would expect to see crossing over between these genes
occur _____ of the time.
a.
2.5%
b.
5%
c.
10%
d.
20%
e.
25%
15. The gene that determines ABO blood type and the gene for nail-patella syndrome are on the same
chromosome. Previous results indicate that the B allele for ABO blood type and the autosomal
dominant nail-patella syndrome are linked. In one particular family, 2 members out of 10 inherited
nail-patella syndrome but did not inherit the B allele. They were the only family members that
inherited only one of the two alleles. What is the distance between the gene for nail-patella syndrome
and the gene for ABO blood group as determined for this family?
a.
5 cM
b.
10 cM
c.
15 cM
d.
20 cM
e.
25 cM
16. This is a method of gene mapping using markers that show differences in restriction enzyme cutting
sites or differences in the number of repeated DNA sequences.
a.
positional cloning
b.
linkage mapping
c.
recombinant DNA mapping
d.
genetic mapping
e.
crossing over mapping
17. This is a collection of DNA fragments that contains all the sequences in a genome.
a.
linkage library
b.
exome library
c.
repetitive DNA library
d.
positional library
e.
genomic library
18. All of the following provide clues to the locations of genes in a DNA sequence EXCEPT
a.
promoter sequences.
b.
stop codons.
c.
analysis of the nucleotide triplets and the corresponding amino acids.
d.
repetitive sequences.
e.
open reading frames.
19. All of the following describe new information learned about the human genome EXCEPT
a.
the human genome has many regions of noncoding DNA.
b.
only about 1.5% of the genome codes for proteins.
c.
the human genome has many regions of repetitive sequences.
d.
transposons make up the majority of the repetitive sequences.
e.
All of these describe new information about the human genome.
20. All of the following are types of repeats found in the human genome EXCEPT
a.
Alu sequences.
b.
LINE 1 sequences.
c.
transposons
d.
STRs.
e.
All of these are repetitive sequences in the genome.
21. The human genome contains
a.
15,000-20,000 genes.
b.
20,000-25,000 genes.
c.
100,000-200,000 genes.
d.
over 500,000 genes.
e.
50,000-100,000 genes
22. How can there be so many more proteins produced by our cells compared to the number of genes that
we have?
a.
RNA processing in the nucleus creates different messenger RNAs from the same original
transcript.
b.
Each protein is encoded by several genes.
c.
Alternative splicing occurs in a small number of genes.
d.
All of the mRNAs produced from a single pre-RNA will contain the same exons.
e.
All of these are correct answers.
23. Gene therapy typically involves all of the following EXCEPT
a.
genetically modified viruses.
b.
the transfer of functional genes into cells.
c.
growth of modified cells in the lab.
d.
transfer of cells back into the body after the gene transfer.
e.
isolation and injection of normal proteins into patients.
24. In 1990, a young girl was treated for severe combined immunodeficiency disorder. Her treatment
involved
a.
genetic modification of red blood cells removed from her body.
b.
insertion of the adenosine deaminase gene into her white blood cells while they were
present in her body.
c.
injection of adenosine deaminase protein.
d.
insertion of the RPE65 allele into her cells.
e.
insertion of the adenosine deaminase gene into white blood cells removed from her body.
25. In a genetic study, researchers find that two genes show the expected linkage in 170 subjects, while 30
subjects show traits that indicate crossing over has occurred. What is the distance between these
genes?
a.
5 cM
b.
10 cM
c.
15 cM
d.
20 cM
e.
25 cM
26. With linkage maps,
a.
distances between genes are determined by sequencing the number of nucleotides between
genes.
b.
the greater the number of cM between genes, the less likely crossing over will occur
between them.
c.
map units are equal to twice the frequency of crossing over.
d.
genes which are closer together show less crossing over between them than those that are
farther apart.
e.
only the relative order of genes is important; the distances are not.
27. Positional cloning
a.
uses random cloning to isolate genes.
b.
starts by sequencing the entire chromosome containing the gene of interest.
c.
makes use of particular markers on the DNA.
d.
makes use of the location of Alu sequences.
e.
All of these are correct answers
TRUE/FALSE
1. The more family pedigrees studied, the more accurate the estimate of the distance between two linked
genes.
2. The number of proteins produced by human cells is much greater than the number of genes present in
the human genome.
3. Gene therapy is currently used to treat many genetic disorders.
4. One of the goals of the HGP is to identify all the proteins encoded by human genes.
5. It is easier to map genes on the autosomes than on the sex chromosomes.
6. The exome accounts for only about 2.5% of the genome.
7. In order for two genes to be linked, they must be located on the same chromosome.
8. The markers used in positional cloning are always genes.
9. Two genes that are genetically linked to each other can be separated by crossing over.
100
10. The functions of almost all of the human genes are currently known.
MATCHING
Match the appropriate term with the description.
a.
Technique used to determine the location of a gene
b.
Particular genes are often inherited jointly
c.
Provides clues to the location of genes
d.
A collection of DNA sequences that represents all regions of the genome
e.
DNA sequences that are useful for identifying the positions of genes
f.
Repetitive DNA with the ability to replicate and move around the genome
g.
Map units of linkage maps
h.
Repetitive sequences that are thought to have played an important role in human evolution
i.
Genetic exchange between chromosomes
j.
Repetitive sequences comprising about 17% of the genome
1. DNA markers
2. Crossing over
3. LINE 1 sequences
4. Promoters
5. Genomic library
6. Centimorgans
7. Alu sequences
8. Positional cloning
9. Linkage
10. Transposon
ESSAY
1. How have SNPs identified by the Human Genome Project been used to locate genes involved in
complex genetic diseases?
Chapter 10 – Genomics
2. What are some of the legal and ethical questions associated with genomics?
SHORT ANSWER
1. What is gene therapy? Describe how gene therapy can be used to correct genetic disorders.
2. Human cells can produce many more proteins that the number of genes present in the genome.
Describe two mechanisms that help to explain this difference.
3. Describe how an Alu sequence insertion may have played a role in human evolution.