MMSC491 exam 2 corrected

Interpret to following chromosome: 46,XX,del(15)(q11q13)

A female with an interstitial deletion on the long arm of chromosome 15 with breakpoints at q11 and q13

Prolonged skin exposure to the sun in the absence of UV protectant is likely to result in which type of DNA damage?

DNA base cross-linking

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

The sequence of a person's beta globin gene.

A compund heterozygote is...

An individual who carries two different mutant alleles

With respect to miRNAs work which of the following statements is false?

A single miRNA normally binds to transcripts from just one target gene

With reference to imprinting disorders, which of the following statements is false?

About one-quarter of individuals with Angelman syndrome lack a paternal chromosome 15.

What stage of clinical trials includes generally less than a hundred patients, while testing for safety and side effects?

Phase 1

Which of the following best describes cytokines?

Chemical messengers that help in intracellular signaling

With respect to Autosomal recessive inheritance which of the following statements is incorrect?

Heterozygotes are always asymptomatic carriers.

With respect to Mosaicism, which of the following statements is false?

Mosaicism is the inevitable consequence of germline mutations

Which of the following is not regularly an epigenetic phenomenon that depends on DNA methylation or chromatin modification?

A position effect in which a gene is silenced by an inversion where both breakpoints occur within a euchromatic environment

Which of the following descriptions is false?

Within an imprinted gene cluster, all genes on one of the two parental chromosomes are silenced, but the equivalent genes on the other parental chromosome are not subject to silencing.

Which of the following is referred to as the introduction of healthy genes into cells, tissues, or organs cultured in vitro and re-implanting them back to the patient?

Ex-vivo therapy

With reference to aberrant methylation of bases which of the following statement is true?

Guanine is occasionally methylated to give O-6-methylguanine which base pairs with adenine rather than with cytidine.

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

Huntingdon's disease

Extensive skin cancer and extreme sensitivity to UV light is observed in patients with Xeroderma Pigmentosum. Based on this phenotype what DNA repair system is likely defective in this disease?

Nucleotide excision repair

A 4-year-old male presents to a neuro-ophthalmology clinic with new onset decreased visual acuityHe has a history of myopathy and sensorineural hearing loss. Dilated eye examination reveals bilateral optic nerve pallor and the visual evoked potentials are delayed indicating a conduction defect in the optic nerve Family history is reviewed and reveals other family members with decreased visual acuity as shown in the pedigree above . The patient's father has a history of decreased visual acuity and an ataxic gait , and he is an only child The paternal grandmother is deceased , but was reported to have had decreased visual acuity The remainder of the family history is unremarkable . What type of inheritance does this pedigree show ?

autosomal dominant (AD) inheritance pattern

Which of the following are two common DNA binding motifs found in DNA proteins involved in the regulation of gene expression?

Zinc finger and leucine zipper

Identify which of the following is an example of augmentation therapy?

Hormone replacement therapy

Which of the following are components of RNA interference?

Both A&B miRNA/siRNA and the RISC complex.

Individuals afflicted with Xeroderma Pigmentosum would be expected to...

Have defective DNA damage repair

How is germline therapy achieved?

Modifying the DNA of gamete, zygote, or early embryo

In a genetic disorder such as fragile X syndrome which is characterized by unstable genetic variation that can increase replication one would expect to see...

Increased severity in successive generations

When an autosomal recessive disorder is quite frequent, carriers will be common. When an offspring is born to two parents who each carry different mutant alleles, the affected offspring who carries two different mutant alleles would be described as a...

Compound heterozygote

The fraction of genetic variation in the nuclear genome that is expected to have a harmful effect on gene function.

1%

Interpret the following chromosome: 46,XY,t(3;17)(q26q23

A male with a balanced reciprocal translocation with breakpoints at 3q26 and 17q23

Consider the picture above which depicts a patient diagnosed with facioscapulohumeral muscular dystrophy (FSHD). Which of the following statements regarding the underlying genetic basis of this disease is true?

Loss of tandem microsatellite repeat regions that epi-regulate the DUX4 gene expression

The ABO blood group is an example of...

Co-dominant trait

Heterochromatin is...

Highly condensed and shows little to no evidence of gene expression

The variable phenotype observed in the mitochondrial disease are due to what genetic phenomena?

Heteroplasmy

Calico cats display respect to orange and black coat color genes

mosaicism

With reference to base cross-linking which of the following statements is false?

The cross-linked bases are on opposing DNA strands

With reference to DNA repair, which of the following statements is false

Repair of double stranded DNA breaks is easier in cells prior to DNA replication than after DNA replication has occurred.

Which type of augmentation therapy is useful for disorders affecting blood cells and some other immune system cells?

Bone marrow transplantation

Which of the following describes the non-viral transfer of DNA, RNA, and oligonucleotides into human or other animal cells?

Transfection

Complete the following statement, Hypomeythlation of DNA is associated with ____?

Chromatin decondensation and transcription activation

Herceptin breast cancer presents with the patient possessing multiple(instead of just two) copies HER2 DNA. This type of genetic variation would be classified as which of the following?

A copy number variant

What results in a copy number variant

SNP

A silent mutation...

Is the result of a conservative mutation that does not lead to a change in the amino acid in the encoded polypeptide, but the change is such that it does not lead to a functional change in the encoded protein.

In which drug development phase is pharmacodynamics being assessed?

Phase 1

Which of the following statements regarding X-chromosome inactivation is true?

Is an epigenetic event which involves gene silencing

Barr bodies are the result of ...

Highly condensed inactive x-chromosomes

With respect to histone modifications which of the following statements is true?

histone acetylation always means adding an acetyl group to the side chain of a lysine residue.

With respect to X-linked recessive inheritance which of the following statements is false?

Women are always asymptomatic.

Which of the following would not be considered an epigenetic mark?

Rna splicing

With respect to female calico cats which of the following statements is true?

Have both maternally and paternally

Which of the following statements is false regarding the sources of genetic variation?

Most of the inherited changes in our DNA arise because of exposure to extracellular mutagens, including radiation sources and chemical mutagens.

With respect to Mitochondria inheritance which of the following statements is false?

All of the statements are true

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

Fragile X

Which type of cancer is explained by the two-hit hypothesis?

Retinoblastoma

Trans-acting factors are...

Protein or RNA

Which of the following is not an example of augmentation therapy?

Corrective surgery for cleft lip and palate

Consider the picture above, at what level is gene expression being modulated?

transcription

Which of the following descriptions is inaccurate? The epigenome ....

does not vary between cells of the same type

If these calico cats were male, we would expect their genotype to be ?

XXY

The study of how people respond differently to drug therapy based upon their genetic makeup is known as:

Pharmacogenetics

Which of the following is incorrect when used in human genetics?

the terms dominant and recessive apply equally to alleles and phenotypes.

Alternative splicing...

Can give rise to multiple isoforms of the same gene

Which of the following is an example of prevention treatment?

Reduction of susceptibility factor

With respect to X chromosome inactivation in females which of the following statements is incorrect?

The process involves epigenetic silencing of each gene on one of the two X chromosomes, either the maternal X chromosome or the paternal X chromosome.

DNA damage Reactive Oxygen Species (ROS) would most commonly be observed in...

Mitochondria

With respect to noncoding RNA(ncRNA), which of the following statements is false?

Most regulatory long ncRNAs work as trans-acting regulators.

A cis-acting element can be...

DNA or RNA

With respect to epimutations, which of the following statements is false, from a practical viewpoint?

A "chromatin disease" is a disorder that is consistently caused by a primary epimutation.