Question 1

How can databases of variants be used to help pinpoint a disease-causing mutation? (Select all that apply. )

Accepted Answer

Databases of variants can help eliminate polymorphisms found in healthy individuals (A) and common polymorphisms unlikely to cause rare diseases (B), narrowing down potential disease-causing mutations.

Question 2

What additional data would increase your confidence that the gene of interest and the DNA marker are linked? (Select all that apply. )

Accepted Answer

Analysis showing a higher ratio of parental to recombinant offspring (as in options C and D) suggests stronger linkage between the gene of interest and the DNA marker.

Question 3

What is the name of the process for removing amniotic fluid from a pregnant mother to obtain fetal cells for genetic testing?

Accepted Answer

Amniocentesis is the process where a small amount of amniotic fluid, which contains fetal tissues, is extracted from the amniotic sac surrounding a developing fetus. This fluid can then be analyzed for genetic abnormalities, making it a crucial procedure for prenatal diagnosis.

Question 4

In 2008, Margaret Binkele was murdered in her Georgia home.The number of repeats at three CODIS simple sequence repeat (SSR)loci were determined using crime scene samples and blood from three suspects.The results are summarized in the table.
Genotypes at three SSR loci
 $$\begin{array} { | c | c | c | c | c | } 
\hline & \text { Crime scerie sarmple } & \text { Suspect 1 } & \text { Suspect 2 } & \text { Suspect 3 } \
\hline \text { SSR locus 1 } & 10,10 & { 8 } , 10 & 6,7 & 10,10 \
\hline \text { SSR locus 2 } & 11,11 & 11,11 & 9,15 & 10,12 \
\hline \text { SSR locus 3 } & 6,9 & 6,7 & 6,9 & 6,9 \
\hline
\end{array}$$
-According to the data, the crime scene sample matches the sample from which suspect?

Accepted Answer

The answer of In 2008, Margaret Binkele was murdered in...

Question 5

Which is a challenge of using pedigrees for positional cloning?

Accepted Answer

Some matings may not be informative because they do not provide enough genetic variation to determine linkage between a trait and genetic markers.

Question 6

Identifying candidates for a disease gene by positional cloning depends on distinguishing DNA markers that are close to the disease gene from markers that are far away.When the disease gene is close to a marker, there will be

Accepted Answer

A low rate of recombination between the disease gene and the marker indicates physical proximity, as genes that are close together on a chromosome are less likely to be separated during recombination events.

Question 7

In 2013, a man was arrested for transporting 400 pounds of marijuana across state lines.His DNA was tested, entered into the CODIS database, and found to match the crime scene sample in the Margaret Binkele case.What additional evidence would increase your confidence that the man arrested for transporting marijuana murdered Margaret Binkele? (Select all that apply. )

Accepted Answer

The answer of In 2013, a man was arrested for...

Question 8

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 6 parental and 3 recombinant offspring

-What is the maximum Lod score for this mating?

Accepted Answer

The answer of Linkage between a gene of interest and...

Question 9

How can microarrays differentiate between a wild-type allele and a disease allele that differ at only one nucleotide?

Accepted Answer

Oligonucleotides on a microarray can be designed to specifically hybridize to sequences with even a single nucleotide difference, allowing differentiation between a wild-type allele and a disease allele that differ by only one nucleotide.

Question 10

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 19 parental and 1 recombinant offspring.
-The results of this mating are sufficient to conclude with confidence that the gene of interest and the DNA marker are linked.

Accepted Answer

The successful transmission of the gene of interest and the DNA marker together in the majority of offspring indicates that these two traits are linked and segregate together.

Question 11

You are studying a disease that is known to be caused by a single nucleotide change in a single gene, although the effect this change ultimately has on the protein's structure and function is unknown.You have DNA samples from multiple patients that you suspect of having this disease.What is the most efficient way to test the samples for the relevant mutation?

Accepted Answer

PCR amplification followed by Sanger DNA sequencing is the most efficient method for identifying a specific single nucleotide change in a gene. PCR amplifies the region of interest, and Sanger sequencing provides the precise sequence, allowing for the identification of the specific mutation.

Question 12

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 19 parental and 1 recombinant offspring.
-What is the maximum Lod score for linkage at this locus?

Accepted Answer

The maximum Lod score for linkage at this locus can be calculated using the formula: Lod = log10[(1 - r)^n / (0.5)^n], where r is the recombination fraction and n is the total number of offspring. In this case, with 19 parental and 1 recombinant offspring, r = 1/20 = 0.05, and n = 20. Plugging these values into the formula gives a Lod score of approximately 6.3, indicating strong evidence for linkage.

Question 13

Herceptin is a drug that is given to treat certain breast cancers.However, it is most effective on tumors that are overexpressing the gene HER2.Which of the following strategies would be best for determining whether Herceptin  would be effective in a given patient?

Accepted Answer

Herceptin is effective in patients whose tumors overexpress the HER2 gene. The best strategy is to determine if the patient's tumor cells have the overexpression allele of HER2, as this directly correlates with the drug's effectiveness.

Question 14

What technique can help identify a disease gene quickly by narrowing the focus?

Accepted Answer

Compare the genome sequences of different species to identify conserved amino acids helps identify a disease gene quickly by narrowing the focus because it allows researchers to identify regions of the genome that are essential for gene function.

Question 15

Which polymorphism is most likely to affect an individual's phenotype?

Accepted Answer

An SNP (Single Nucleotide Polymorphism) in the start codon of a protein-coding gene is most likely to affect an individual's phenotype because the start codon is crucial for initiating translation. Alterations here can disrupt the production of the encoded protein, directly impacting the phenotype.

Question 16

Which is part of a DNA sequencing technique that is useful for high-throughput sequencing, but is not part of Sanger DNA sequencing?

Accepted Answer

Sanger sequencing does not involve the removal of a chemical group that blocks the 3′ end of the new DNA strand. This step is characteristic of some high-throughput sequencing techniques, such as Illumina sequencing, where reversible terminator bases are used.

Question 17

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 6 parental and 3 recombinant offspring

-The results of this mating are sufficient to conclude with confidence that the gene of interest and the DNA marker are linked.

Accepted Answer

With only 9 offspring, the sample size is too small to confidently conclude linkage between the gene of interest and the DNA marker. Generally, a larger sample size is needed to accurately determine genetic linkage, as it provides more statistical power to detect a true linkage versus random assortment.

Question 18

In the United States, most newborns undergo a screening test for up to 60 genetic disorders.A few drops of blood is taken from each baby and the levels of various blood components are determined.The screening identifies babies who might have a genetic disorder, but is not diagnostic.Further testing is required if the screen shows a blood component is out of the normal range.Which of the following technologies could potentially be a low-cost replacement for the current newborn screening and would directly test most babies for the presence of many genetic disorders?

Accepted Answer

Exome sequencing and comparison with known mutations in databases can directly test for the presence of many genetic disorders by analyzing the coding regions of genes where most disease-causing mutations occur. This approach can potentially be a low-cost replacement for the current newborn screening as it allows for the identification of a wide range of genetic disorders in a single test.

Quiz 11: Analyzing Genomic Variation

How can databases of variants be used to help pinpoint a disease-causing mutation? (Select all that apply. )

What additional data would increase your confidence that the gene of interest and the DNA marker are linked? (Select all that apply. )

What is the name of the process for removing amniotic fluid from a pregnant mother to obtain fetal cells for genetic testing?

Which is a challenge of using pedigrees for positional cloning?

Identifying candidates for a disease gene by positional cloning depends on distinguishing DNA markers that are close to the disease gene from markers that are far away.When the disease gene is close to a marker, there will be

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 6 parental and 3 recombinant offspring -What is the maximum Lod score for this mating?

How can microarrays differentiate between a wild-type allele and a disease allele that differ at only one nucleotide?

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 19 parental and 1 recombinant offspring. -The results of this mating are sufficient to conclude with confidence that the gene of interest and the DNA marker are linked.

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 19 parental and 1 recombinant offspring. -What is the maximum Lod score for linkage at this locus?

Herceptin is a drug that is given to treat certain breast cancers.However, it is most effective on tumors that are overexpressing the gene HER2.Which of the following strategies would be best for determining whether Herceptin would be effective in a given patient?

What technique can help identify a disease gene quickly by narrowing the focus?

Which polymorphism is most likely to affect an individual's phenotype?

Which is part of a DNA sequencing technique that is useful for high-throughput sequencing, but is not part of Sanger DNA sequencing?

Linkage between a gene of interest and a DNA marker is being studied. A mating results in 6 parental and 3 recombinant offspring -The results of this mating are sufficient to conclude with confidence that the gene of interest and the DNA marker are linked.