Question 1

When a chromosome lacking 4 million base pairs is inherited from the mother, the child is at risk for developing which syndrome?&#10;A)Prader-Willi&#10;B)Angelman&#10;C)Beckwith-Wiedemann&#10;D)Russell-Silver

Accepted Answer

This anomaly illustrates the inheritance pattern of Angelman syndrome, which can be caused by a deletion of 4 million base pairs from chromosome 15q when inherited from the mother. The anomaly is not the cause of any of the other syndromes, although the same gene deletion when inherited from the father does lead to Prader-Willi syndrome.

Question 2

What is the difference between DNA sequence mutations and epigenetic modifications?&#10;A)DNA sequence mutations can be directly altered.&#10;B)Leukemia is a result of only DNA sequence mutation.&#10;C)Epigenetic modifications potentially can be reversed.&#10;D)No known drug therapies are available for epigenetic modifications.

Accepted Answer

Unlike DNA sequence mutations, which cannot be directly altered, epigenetic modifications can be reversed. The remaining options are not true statements regarding the difference between DNA sequence mutations and epigenetic modifications.

Question 3

What genetic process is likely responsible for the occurrence of asthma in only one of a pair of identical twins?&#10;A)Epigenetic modifications&#10;B)Genomic imprinting&#10;C)Transgenerational inheritance&#10;D)Methylation

Accepted Answer

Epigenetic modifications can cause individuals with the same deoxyribonucleic acid (DNA) sequences (such as identical twins) to have different disease profiles. Imprinting means that either the copy of a gene inherited through the sperm or the copy inherited through the egg is inactivated and remains in this inactive state in all of the somatic cells of the individual. The heritable transmission to future generations of epigenetic modifications is called transgenerational inheritance. DNA methylation occurs through the attachment of a methyl group to the carbon-5 position of a cytosine.

Question 4

A child's diagnosis of Beckwith-Wiedemann syndrome is supported by the presence of what? (Select all that apply.)&#10;A)An omphalocele&#10;B)Neonatal hypoglycemia&#10;C)Creased earlobes&#10;D)Low birth weight&#10;E)A large tongue

Accepted Answer

Beckwith-Wiedemann syndrome is usually identifiable at birth because the child exhibits a large size for gestational age, neonatal hypoglycemia, a large tongue, creases on the earlobe, and omphalocele.

Question 5

What can a malfunction in DNA methylation lead to?&#10;A)Hypothyroidism&#10;B)Blindness&#10;C)Cancer&#10;D)Diabetes mellitus

Accepted Answer

Aberrant methylation can lead to silencing of tumor-suppressor genes in the development of cancer. No research supports a connection between hypothyroidism, blindness, or diabetes mellitus to a malfunctioning of DNA methylation.

Question 6

What is the belief regarding twins who adopt dramatically different lifestyles?&#10;A)They may experience very different aging processes.&#10;B)They will retain very similar methylation patterns.&#10;C)They will experience identical phenotypes throughout their lifespans.&#10;D)They may never demonstrate similar DNA sequences of their somatic cells.

Accepted Answer

Twins with significant lifestyle differences (e.g., smoking versus nonsmoking) accumulate large numbers of differences in their methylation patterns. The twins, despite having identical DNA sequences, become more and more different as a result of epigenetic changes, which in turn affect the expression of genes. These results, along with findings generated in animal studies, suggest that changes in epigenetic patterns may be an important part of the aging process. They will not experience identical phenotypes throughout their life spans.

Question 7

What do hypomethylation and the resulting effect on oncogenes result in?&#10;A)A decrease in the activity of the oncogene, thus suppressing cancer development.&#10;B)A deactivation of MLH1 to halt DNA repair.&#10;C)An increase in tumor progression from benign to malignant.&#10;D)An over-expression of microRNA, resulting in tumorigenesis.

Accepted Answer

Tumor cells typically exhibit hypomethylation (decreased methylation), which can increase the activity of oncogenes. Hypomethylation increases as tumors progress from benign neoplasms to malignancy. Hypomethylation does not result in suppressed cancer development, deactivation of MLH1, or over-expression of micro-RNA.

Question 8

What is most likely the shape of the face of a child diagnosed with Russell-Silver syndrome?&#10;A)Round&#10;B)Square&#10;C)Triangular&#10;D)Elongated

Accepted Answer

Growth retardation, proportionate short stature, leg-length discrepancy, and a small, triangular-shaped face characterizes Russell-Silver syndrome. The other face shapes are not characteristic of Russell-Silver syndrome.

Question 9

What are genes responsible for the maintenance of all cells referred to as?&#10;A)Universal&#10;B)Managerial&#10;C)Housekeeping&#10;D)Executive

Accepted Answer

A small percentage of genes, termed housekeeping genes, are necessary for the function and maintenance of all cells. The remaining options do not accurately refer to these cells.

Question 10

Which statement is true regarding the embryonic development of stem cells?&#10;A)They are already differentiated.&#10;B)They are referred to as housekeeping genes.&#10;C)They already demonstrate DNA sequencing.&#10;D)They are said to be totipotent.

Accepted Answer

Early in embryonic development, all cells of the embryo have the potential to become any type of cell in the fetus or adult. These embryonic stem cells are said to be totipotent. They are not yet differentiated. Housekeeping genes are necessary for the function and maintenance of all cells. DNA sequencing is not limited to embryonic stem cells.

Question 11

When microRNA (miRNA) are methylated their messenger RNA (mRNA) targets are over-expressed. What would be the resulting effect on existing cancer?&#10;A)Cell death&#10;B)Metastasis&#10;C)Remission&#10;D)Relapse

Accepted Answer

The answer of When microRNA (miRNA) are methylated their messenger...

Question 12

A diagnosis of Angelman syndrome in a child is supported by which assessment findings? (Select all that apply.)&#10;A)Small feet and hands&#10;B)Profound intellectual disability&#10;C)Obesity&#10;D)Ataxic gait&#10;E)History of seizures

Accepted Answer

The answer of A diagnosis of Angelman syndrome in a...

Question 13

Which term refers to the silenced gene of a gene pair?&#10;A)Activated&#10;B)Altered&#10;C)Mutated&#10;D)Imprinted

Accepted Answer

The answer of Which term refers to the silenced gene...

Question 14

Prader-Willi syndrome causes a chromosomal defect that is what?&#10;A)Initiated by postnatal exposure to a virus&#10;B)Inherited from the father&#10;C)Related to maternal alcohol abuse&#10;D)Transferred from mother to child

Accepted Answer

The answer of Prader-Willi syndrome causes a chromosomal defect that...

Deck 6: Epigenetics and Disease