MMSC491 EXAM 2 Latest Update 2024-2025 300

MMSC491 EXAM 2 Latest Update 2024-2025 300 Questions and 100% Verified Correct Answers Guaranteed A+ At First Attempt

A class of mutation that is quite frequently associated with a gain of function.

• a post-zygotic (somatic) mutation
• a missense mutation
• a dynamic mutation

d. a premutation - CORRECT ANSWER: b

A mutation that does not cause a disease but that is unstable at mitosis and meiosis and can change into a pathogenic mutation.

• a post-zygotic (somatic) mutation
• a missense mutation
• a dynamic mutation

d. a premutation - CORRECT ANSWER: d

A nonsense mutation would be expected to result in .....

• Production of a polypeptide shorter than normally expected
• Production of a gene product with a amino acid substitution
• No change in the encoded polypeptide
• Alter the regulation of gene expression of the encoded polypeptide. - CORRECT

ANSWER: a

A pathogenic mutation that is unstable at mitosis and meiosis and can result in progressively severe phenotypes.

• a post-zygotic (somatic) mutation
• a missense mutation
• a dynamic mutation

d. a premutation - CORRECT ANSWER: c

A person's ability to absorb or metabolize a drug that is intended to treat a genetic disorder is entirely due to genetic factors.

• True

b. False - CORRECT ANSWER: b

A person's ability to absorb or metabolize a drug that is intended to treat a genetic disorder is not modified by having a bacterial infection.

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• True

b. False - CORRECT ANSWER: b

A silent mutation....

• is a mutation which lead to silencing of the gene expression of the encoded

polypeptide

• results in a mutated coded that specifies the same amino acid as the original codon.
• results in a mutated coded is different than the same amino acid as the original

codon.

• is the result of a conservative mutation that does not lead to a change in the amino

acid in the encoded polypeptide, but the changes is such that it does not lead to a

functional change in the encoded protein - CORRECT ANSWER: b

A type of mutation that results in genetic mosaicism.

• a post-zygotic (somatic) mutation
• a missense mutation
• a dynamic mutation

d. a premutation - CORRECT ANSWER: a

Assisted reproductive technology studies modeled in mice have demonstrated....

• intracytoplasmic sperm injection induces primary epimutations
• altered the patterns of DNA methylation
• altered imprinting patterns that are transmitted to subsequent generations.

d. modified splice site junctions - CORRECT ANSWER: a

Concerning the efficacy of small molecule drugs, which, if any, of the following statements is true?

• At the level of clinical trials drugs can vary widely in how effective they are.
• Once a drug has received regulatory approval, we can be sure that it will be effective

in all patients, although some people will receive more benefit from it than others.

• Drugs used to treat psychiatric disorders are particularly effective.
• Stains and beta blockers that were meant to reduce the risk of heart disease are

good examples of drugs that are largely ineffective. - CORRECT ANSWER: a

Gain of function missense mutations in the RET gene which encodes a tyrosine kinase protein result in ....

• Hirschsprung's disease
• Downs syndrome
• Kliefelter syndrome
• medullary thyroid carcinoma or multiple endocrine neoplasia - CORRECT ANSWER:

d 2 / 4

In cystic fibrosis, the p.Phe580del mutation leads to....

• Abnormal regulation of gene expression.
• Aberant protein folding, leading to protein miss-folding and improper cellular

localizaiton.

• Abnormal splicing.

d. Protein aggregation and cell lysis. - CORRECT ANSWER: b

Interpret the following chromsome: 46,XX,del(15)(q11q13)

• A cell from a female that contains a marker chromosome (an extra unidentified

chromosome)

• A male carrier of a Robertsonian translocation that has arisen via breakpoints on the

short arms of chromosomes 13 and 14 (q0 is not a chromosome band; it means the centromere).

• A female with an interstitial deletion on the long arm of chromosome 15 with

breakpoints at q11 and q13.

• A male with a balanced reciprocal translation with breakpoints at 3q26 and 17q23. -

CORRECT ANSWER: c

Purifying selection results in which of the following?

• Removes harmful alleles from the population
• Amplifies genes which can compensate for the loss of function mutant allele
• Increases the frequency of a fitness conferring gene in the population
• The process by which DNA is purified to carry out genetic testing. - CORRECT

ANSWER: a

The term phenotype can be applied to a wide range of manifestations. Which of the following properties, if any, do not constitute a phenotypic manifestation?

• The number of digits a person has.
• The transcriptome of a single T cell.
• The sequence of a persons beta globin gene.

d. autistic behavior - CORRECT ANSWER: c

What approximately is the fraction of genetic variation in the nuclear genome that is expected to have a harmful effect on gene function?

• 50%
• 25%
• 10%

d. 1% - CORRECT ANSWER: d

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What type of stain is traditionally used to visualize metaphase chromosomes in preparing a karyotype?

• Silver
• Coomassie
• Giemsa

d. Xylene cyanol - CORRECT ANSWER: c

Which of the following amino acid substitutions would be considered to be a conservative substitution if the original amino acid was Arg?

• Lysine (Arg), (R)
• Serine (Ser), (S)
• Tyrosine (Tyr), (Y)

d. Glutamine, (Gln), Q - CORRECT ANSWER: a

Which of the following autosomal trisomies are not compatible with life?

• 13, 18, and 21
• 45X
• 46XXY

d. 46XY+16 - CORRECT ANSWER: d

Which of the following is a disease whose molecular basis is an unstable expansion of short noncoding tandem repeats?

• Kennedy disease
• Huntington disease
• Prader-Willi syndrome

d. Fragile X syndrome - CORRECT ANSWER: d

Which of the following is a disease whose molecular basis is caused by a gene-pseudo gene sequence exchange?

• Steroid 21-hydroxylase deficiency
• Hemophilia A
• Sickle cell animia

d. Amyotrophic lateral sclerosis - CORRECT ANSWER: a

Which of the following is a disease whose molecular basis is due to the unstable expansion of CAG repeats encoding polyglutamine?

• Hand-foot genital syndrome
• Oculopharyngeal muscular dystrophy
• Huntington disease

d. Synpolydactyly type II - CORRECT ANSWER: c

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