Question 1

You are working in a lab where you are studying a disease that is known to be caused by a single nucleotide change, although the effect this change ultimately has on the protein's structure/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

DNA sequencing is the most efficient way to identify the single nucleotide change in the patients' DNA samples. This will allow for the identification of the specific nucleotide change and the potential effects it may have on the protein's function/structure. Western blotting is a technique used to detect the presence of a specific protein but would not directly identify the nucleotide change. Karyotyping is used to visualize the chromosome number and structure, and would not be useful in identifying a single nucleotide change. Amniocentesis is a procedure used during pregnancy to collect amniotic fluid for testing genetic disorders, but would not be relevant for patients already diagnosed with the disease.

Question 2

Checkpoint proteins act as ________.

Accepted Answer

Checkpoint proteins are involved in cell cycle checkpoints, which help to ensure that DNA is replicated and repaired correctly before cell division occurs. Thus, checkpoint proteins act as tumor-suppressing genes by preventing cells with damaged DNA from proliferating and potentially becoming cancerous.

Question 3

In the United States, most newborns undergo a test for primary congenital hypothyroidism, a condition where people are unable to produce enough thyroid hormone. On a nationwide basis, this is an example of

Accepted Answer

The test for primary congenital hypothyroidism is an example of genetic screening, which is the process of testing a population to identify individuals who may be at increased risk for a genetic disorder. It is different from genetic testing, which is usually performed on an individual who already has symptoms or a family history of a genetic disorder. Amniocentesis and preimplantation genetic diagnosis are both forms of prenatal genetic testing, which are not applicable in this scenario since the newborns have already been born.

Question 4

The general approach in which researchers and clinicians use methods that enable them to understand the molecular changes that occur in diseases such as cancer is called _________.

Accepted Answer

Molecular profiling is the general approach used by researchers and clinicians to understand the molecular changes that occur in diseases such as cancer. Personalized medicine is a more specific approach within molecular profiling that aims to tailor treatments based on an individual's molecular profile. DNA microarrays and cluster analysis are specific techniques used within molecular profiling to analyze gene expression and identify patterns of molecular changes in diseases.

Question 5

An oncogene may promote cancer by keeping the cell growth pathway in the off position.

Accepted Answer

Oncogenes promote cancer by stimulating cell growth and division, not by keeping the growth pathway turned off. Tumor suppressor genes are responsible for keeping cell growth in check and preventing cancer.

Question 6

Chronic myelogenous leukemia is an example of a proto-oncogene activation by ____.

Accepted Answer

Chronic myelogenous leukemia results from a translocation between chromosomes 9 and 22, which creates the Philadelphia chromosome and activates the BCR-ABL fusion protein, a constitutively active tyrosine kinase that drives leukemic cells' proliferation.

Question 7

When are caspases active?

Accepted Answer

Caspases are activated during apoptosis, which is a genetically controlled process of cell death. They play a key role in breaking down cellular components during apoptosis. They are not active during the normal cell cycle or DNA replication. While some viruses can activate caspases during their replication, viral integration is not a known mechanism for caspase activation.

Question 8

DNA damage is sensed by E2F at the G₁ and G₂ checkpoints.

Accepted Answer

DNA damage is sensed by proteins such as ATM and ATR, not E2F, which is a transcription factor involved in cell cycle regulation.

Question 9

A pedigree analysis is the study of family trees to establish patterns of inheritance.

Accepted Answer

A pedigree analysis involves examining family trees to identify patterns of inheritance and understand the genetic factors that contribute to a particular trait or disorder. It can be used to track the transmission of genetic diseases or traits over multiple generations within a family.

Question 10

An oncogene form of Ras would have ___________.

Accepted Answer

Oncogenic forms of Ras have decreased GTPase activity, which means they are less able to hydrolyze GTP to GDP. This results in the Ras protein being "stuck" in its active GTP-bound state, continuously signaling for cell growth and division, which can lead to cancer.

Question 11

Haplotypes between homologs in the same individual _________; haplotypes for the same chromosome in different individuals ________.

Accepted Answer

Haplotypes between homologs in the same individual can be the same or different, depending on whether or not the individual is homozygous or heterozygous for a particular gene or chromosome region. On the other hand, haplotypes for the same chromosome in different individuals can also be the same or different, depending on whether or not the individuals share common ancestry or have undergone recombination events. Therefore, choice B is the most accurate regarding the variability of haplotypes within and between individuals.

Question 12

When a scientist is attempting to use haplotype analysis to link a disease-causing allele to a molecular marker, it is important for the marker to be close to the disease-causing allele, otherwise _____ may occur.

Accepted Answer

Crossing over is more likely to occur between two genes the further apart they are on a chromosome, which can disrupt the association between a disease-causing allele and a molecular marker if they are not closely linked. This makes it harder to use haplotype analysis for linking the disease-causing allele to the marker.

Question 13

Herceptin is a drug that is given to treat certain breast cancers. However, it is most effective on tumors that are overexpressing HER2. Therefore, patients are tested for HER2 overexpression before being given Herceptin. This is an example of

Accepted Answer

This is an example of personalized medicine because the treatment is specifically tailored to the individual patient based on their unique genetic makeup and HER2 expression levels.

Question 14

In a cell culture you notice that a group of cells have begun to form a focus on a culture dish. These cells are most likely ______.

Accepted Answer

Formation of a focus, or a clustered group of cells, is a common characteristic of transformed or cancerous cells in cell culture. Normal, healthy cells typically grow in a monolayer and do not form foci. Therefore, the most likely option in this scenario is that the cells forming a focus are malignant.

Question 15

A disease that can be caused by mutations in different genes is said to have homogeneity.

Accepted Answer

A disease that can be caused by mutations in different genes is said to have heterogeneity, not homogeneity.

Quiz 24: Medical Genetics and Cancer

Checkpoint proteins act as ________.

In the United States, most newborns undergo a test for primary congenital hypothyroidism, a condition where people are unable to produce enough thyroid hormone. On a nationwide basis, this is an example of

The general approach in which researchers and clinicians use methods that enable them to understand the molecular changes that occur in diseases such as cancer is called _________.

An oncogene may promote cancer by keeping the cell growth pathway in the off position.

Chronic myelogenous leukemia is an example of a proto-oncogene activation by ____.

When are caspases active?

DNA damage is sensed by E2F at the G₁ and G₂ checkpoints.

A pedigree analysis is the study of family trees to establish patterns of inheritance.

An oncogene form of Ras would have ___________.

Haplotypes between homologs in the same individual _; haplotypes for the same chromosome in different individuals .

When a scientist is attempting to use haplotype analysis to link a disease-causing allele to a molecular marker, it is important for the marker to be close to the disease-causing allele, otherwise _____ may occur.

Herceptin is a drug that is given to treat certain breast cancers. However, it is most effective on tumors that are overexpressing HER2. Therefore, patients are tested for HER2 overexpression before being given Herceptin. This is an example of

In a cell culture you notice that a group of cells have begun to form a focus on a culture dish. These cells are most likely ______.

A disease that can be caused by mutations in different genes is said to have homogeneity.

Quiz 24: Medical Genetics and Cancer

Checkpoint proteins act as ________.

In the United States, most newborns undergo a test for primary congenital hypothyroidism, a condition where people are unable to produce enough thyroid hormone. On a nationwide basis, this is an example of

The general approach in which researchers and clinicians use methods that enable them to understand the molecular changes that occur in diseases such as cancer is called _________.

An oncogene may promote cancer by keeping the cell growth pathway in the off position.

Chronic myelogenous leukemia is an example of a proto-oncogene activation by ____.

When are caspases active?

DNA damage is sensed by E2F at the G1 and G2 checkpoints.

A pedigree analysis is the study of family trees to establish patterns of inheritance.

An oncogene form of Ras would have ___________.

Haplotypes between homologs in the same individual _________; haplotypes for the same chromosome in different individuals ________.

When a scientist is attempting to use haplotype analysis to link a disease-causing allele to a molecular marker, it is important for the marker to be close to the disease-causing allele, otherwise _____ may occur.

Herceptin is a drug that is given to treat certain breast cancers. However, it is most effective on tumors that are overexpressing HER2. Therefore, patients are tested for HER2 overexpression before being given Herceptin. This is an example of

In a cell culture you notice that a group of cells have begun to form a focus on a culture dish. These cells are most likely ______.

A disease that can be caused by mutations in different genes is said to have homogeneity.

DNA damage is sensed by E2F at the G₁ and G₂ checkpoints.

Haplotypes between homologs in the same individual _; haplotypes for the same chromosome in different individuals .