Chapter 24 & 20 genetics
Which of the following are common uses of gene cloning?
- Cloned genes can be used in trials of gene therapy. - Cloned genes can be introduced into bacteria to make medicines - The expression of a cloned gene can be used to discover its cellular function
What are the necessary components of a plasmid used in cloning? ( Check all that apply.)
-An origin of replication -A selectable marker -Unique restriction sites
Select the human disorders that are inherited in an autosomal recessive fashion
-Cystic fibrosis -Phenylketonuria -Sickle cell disease
After Cas9 makes a double strand break, which characteristics are observed for repair of the break by nonhomologous end joining (NHEJ)?
-Frameshift mutation may occur in the coding sequence of the gene. -The break region may incur a small deletion.
After Cas9 makes a double strand break, which characteristics are observed for repair of the break by homologous recombination repair (HRR)?
-Researcher includes donor DNA that is homologous to the region where the break occurs. -Can be used to make a specific point mutation
When the CRISPR-Cas system is used for gene mutagenesiswhich two components are combined in the single guide (sgRNA)
-crRNA -tracrRNA
CRISPR-Cas technology has been used to mutate genes in
-human cell lines -roundworms -adult mice -plant cells -mouse embryos
Place the steps by a cloned gene is transferred into human cells using a retroviral technique in order, with the first step at the top
1. A gene of interest is placed into a viral vector. 2. The virus is taken up by cells via endocytosis. 3. The viral coat disassembles, releasing the viral genome into the cytosol. 4. The genome is reverse-transcribed into DNA 5. The viral DNA is imported into the nucleus 6. The gene of interest is integrated into a chromosome of the target cell by recombination
Order the following steps in cloning a gene, putting the first step at the top
1. Chromosomal DNA and cut with a restriction enzyme; the plasmid DNA cut with the same enzyme 2. The digested chromosomal DNA and plasmid DNA are incubated together. 3. Ligation by DNA ligase.
Haplotypes 5 individuals are shown below. Individual #1 and #3 have a particular disease. Which haplotypes are associated with the disease? 1: 1A 2B 3C 4B/1A 2B 3A 4C 2: 1A 2C 3B 4B/1B 2A 3B 4A 3: 1B 2A 3A 4B/1C 2B 3A 4A 4: 1B 2C 3B 4B/1A 2C 3A 4C 5: 1A 2A 3A 4C/1B 2A 3B 4A
2B and 3A
Which best describes a haplotype
A haploid genotype showing linkage of alleles or molecular markers along a single chromosome
In gene cloning, what is the vector?
A small DNA molecule that can replicate independently within a host cell
Which choice is NOT a feature of an autosomal recessive inherited trait
Any affected offspring will always have two affected parents
Site-directed mutagenesis allow a researcher to make a mutation
At a specific sequence of DNA
You wish to introduce a specific missense mutation into a specific cell type in live adult mice. What is the best way to achieve this goal?
CRISPR-Cas technology with donor DNA
Suppose a disease-causing allele shows autosomal recessive inheritance. How could a carrier of this disease-causing allele be Identified?
Carriers often show reduced activity for the enzyme encoded by the allele
Which method can identify genes that are active in cancer cells but inactive in normal cells?
DNA microarray analysis
Regions of only DNA that are bound by a specific protein.
DNase I Footpringing
Determine if a protein binds to a specific RNA or DNA segment
Electrophoretic mobility shift assay (EMSA)
Genetic diseases are spread by shared environmental conditions
False
Genetic testing is used to determine whether a(n) _________has a disease causing gene, while genetic screening is used determine how frequently the gene is found in a(n) _______
Individual; population
What types of human diseases are the most straightforward targets for gene therapy?
Inherited diseases involving a single gene abnormality
Which of the following is pharmaceutical product that is produced by bacteria expressing the human gene?
Insulin
What does the enzyme DNA ligase do?
It covalently links the sugar-phosphate backbone of DNA
The most common nonvirol technique to transfer a cloned gene into human cells involves lipid vesicles called
Liposomes
____________ PCR allows one to assess the amount of DNA produced during a PCR amplification as it is happening
Real time
What is the technique that allows one to determine the amount of template DNA present when the PCR cycles began?
Real-time PCR
__________ DNA technology uses in vitro molecular techniques that combine DNA fragments to produce novel arrangements .
Recombinant
How is site-directed mutagenesis useful in the study of genes and proteins?
The mutated gene can be introduced into a living organism to see how the mutation affects the organism
The major disadvantage to using viral vectors to transfer cloned genes is _______
The potential for immune response
What is recombinant DNA technology?
The production of new arrangements of DNA
Gene ______ is the introduction of cloned genes into somatic cells to treat disease
Therapy
The polymerases used for PCR function at very high temperatures
True
In dideoxyribonucleotides, ______ oxygens are removed from the sugar compared with ribose.
Two
The autosomal recessive human disorder albinism (type I) is caused by a mutation in the gene for _______
Tyrosinase
A small DNA molecule that can replicate Independently within a host cell and thus make many copies of an inserted gene is called a
Vector
Scientists have been working on reducing the Inflammatory response evoked by ______vectors, to improve the safety of gene therapy
Virus, viral, adenovirus, adenoviral, retrovirus, or retroviral
Transformation occurs when
competent cells take up DNA from the medium
Restriction endonucleases are used in gene cloning to
cut the DNA backbone prior to inserting the DNA to be cloned
Molecular profiling is
identification of the genes that play a role in the development of a specific type of cancer
The use of information about a patient's genotype in order to select a medication or therapy that is specifically suited to the patient is called
personalized medicine
Pharmacogenetics is the
study of genetic variations that cause differing responses to drugs
The natural function of the CRISPR -Cas system in bacteria is to
to provide defense against bacteriophages
Place the steps by which a cloned gene is transfered into human cells via liposomes in order, with the first step at the top
1. The DNA containing the gene of interest is complexed with liposomes. 2. DNA liposome complexes are taken into cells via endocytosis. 3. DNA is released into the cytosol 4. DNA is imported into the nucleus. 5. DNA is integrated into a chromosome of the target cell by recombination
Which component in the CRISPR-Cas9 system makes a double-strand break in DNA?
Cas9
DNA microarrays can be used to _______
Compare gene activity in cancer cells and normal cells
DNA sequencing enables researchers to determine the order of __________ in a gene
DNA nucleotides
This technique enables researchers to determine the DNA bases in genes and other chromosomal regions
DNA sequencing
In a DNase footprinting experiment, why does the experimental design only allow DNase I to make a single cut in the DNA fragments?
DNase I cuts the DNA fragment to generate fragments of various sizes
A disease with a genetic origin in a mouse is unlikely to be an inherited disease in humans
False
Both members of identical and fraternal twin have the same likelihood of expressing the same genetic disease.
False
Genetic diseases occur at the same rate in all human populations.
False
PCR stands for primer chain reaction
False
Match the life stage on the left to the type of screening on the right that would be used to detect a genetic disease
Fetus= Amniocentesis and karyotyping to detect chromosomal abnormalities Newborn baby= Test for excess phenylalanine demonstrating phenylketonuria (PKU) Adult= Test for carrier status if one belongs to a family with a history of a specific disease
A single individual who first had disease-causing allele is called a
Founder
The linkage of alleles or molecular markers along a single chromosome is called a
Haplotype
When cloning gene into a vector, the sugar-phosphate backbone of each DNA molecule is covalently linked by the enzyme DNA
Ligase
A major advantage of CRISPR-Cas technology over site-directed mutagenesis is that it can be used directly on _____ cells
Living
A situation where a disease may be caused by mutations in two or more different genes is called
Locus heterogeneity
The disease hemophilia is caused by a deficiency in any one of three blood factors. Two of these factors are encoded by genes the X chromosome and the other foctor gene is located on an autosome. Since mutations in more than one gene can cause hemophilia, this represents
Locus heterogeneity
A major disadvantage of using liposomes as vectors to transfer cloned genes is
Low gene transfer efficiency
The process of identifying genes that play a role in the development of specific type of cancer is called
Molecular profiling
In gene mutagenesis by CRISPR-Cas, a DNA break can be repaired by ________ end _________ or homologous ___________
Nonhomologous, joining, recombination repair
Detect specific types of RNA within a mixture of RNA's
Northern blotting
What tool do scientists use to follow a human pattern of inheritance from generation to generation?
Pedigree analysis
When a human disease caused by a mutation in a single gene, scientist follow the pattern of inheritance by analyzing charts called human
Pedigrees
The study of genetic variations that cause differing responses to drugs is called _____
Pharmacogenetics
A small circular DNA molecule that is often used as a vector in gene cloning is called a(n)
Plasmid
Enzymes that bind to a specific DNA sequence and cut the DNA backbone are called
Restriction enzymes
The enzyme _______ is used when PCR is employed to detect and quantify the amount a specific RNA
Reverse Transcriptase
A resistance gene that allows a host cell containing a vector to grow on a toxic substance is called a(n)
Selectable marker
When a defect in a single gene causes a human disease, the mutant gene often follows
Simple Mendelian Inheritance patterns
When the CRISPR-Cas system is used for gene mutagenesis, tractRNA and crRNA are linked together in a molecule called the ________________ RNA
Single guide
Which of these is a common example of widespread genetic screening of newborns to identify certain disorders
Test for excess phenylalanine indicating phenylketonuria (PKU)
Which of these is a common example of widespread genetic screening of newborns to identity certain disorders?
Test for excess phenylalanine indicating phenylketonuria (PKU)
To study the distribution of disease-causing genes, genetic ______ refers to determining if an individual carries the faulty gene, while genetic _______ relates to assessing the presence of the gene throughout a population.
Testing: screening
When cloning a gene, why must the chromosomal DNA and the plasmid DNA be cut with the same restriction enzyme
The sticky ends of the plasmid DNA will be complementary to the sticky ends of the chromosomal DNA.
Why does incorporation of a dideoxynucleotide into a growing DNA polymer terminate strand synthesis?
There is no longer a free 3' hydroxyl to which to add the next nucleotide
Approximately how many human diseases have a genetic basis?
Thousands
What is the purpose of Northern blotting?
To identify a specific RNA molecule within a mixture of RNA molecules
The natural function of the CRISPR-Cas system in bacteria is to
To provide defense against bacteriophages
The process by which competent cells take up DNA from the extracellutar medium is called
Transformation
Genetic diseases often show a specific age of onset
True
Genetic disorders are more common in families with one affected member as compared to the general population.
True
Many human and animal genetic disorders share similar characteristics.
True
Most genetic diseases have a specific age of onset
True
In which way are viruses used for gene transfer different from their wild-type counterparts?
Viruses used in gene transfer cannot replicate within target cells.
Find a certain protein within a mixture of proteins
Western Blotting
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Tay Sachs disease is inherited with an autosomal recessive allele that leads to a defect in the enzyme hexosaminidase A. When cells are collected from patients, cells with different genotypes exhibit different amounts of enzymatic activity. Rank the amount of enzymatic activity that would be detected in a blochemical assay on cells from patients of these genotypes, with the genotype producing the LEAST amount of enzymatic activity on top
1. Homozygous recessive 2. Heterozygous 3. Homozygous dominant
An advantage of using liposomes as vectors to transfer cloned genes is that liposomes
Do not elicit an immune response
When CRISPR-Cas is used for gene mutagenesis, what type of change does Cas9 make in the gene of Interest?
Double-strand break
A geneticist cannot make sense of a pedigree he has put together for a newly discovered disease that he suspects is transmitted genetically. One possible explanation is
Locus heterogeneity
If a scientist wanted to determine how a specific mutation in a gene of interest affected an organism, what technique would be most useful?
Site-directed mutagenesis
__________ allows a researcher to produce a mutation at a specific sequence
Site-directed mutagenesis
In the CRISPR-Cas system, what part of the sgRNA is designed to be complementary to the gene to be mutated?
Spacer region
What technique is used to identify a particular protein in a mixture of proteins?
Western Blotting
You wish to determine a protein made at a particular stage of development. What technique would you use?
Western blotting
You can PCR amplify a DNA fragment even if you do not have any idea of the sequence of the fragment.
False