MMSC491 EXAM 2 QUESTIONS WITH ANSWERS

MMSC491: EXAM 2 QUESTIONS WITH |\ |\ |\ |\ |\




ANSWERS


1. Which of the following statements is false regarding the
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sources of genetic variation? |\ |\ |\




a. Most of the inherited changes in our DNA arise because of
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exposure to extracellular mutagens, including sources of
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chemical mutagens |\




b. Significant chemical damage is sustained by DNA because of
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its proximity to water molecules in our cells
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c. Most of the inherited changes in our DNA arise because of
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unavoidable endogenous errors in cellular mechanisms and |\ |\ |\ |\ |\ |\ |\


harmful effects on certain natural molecules and atoms within
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our cells |\




d. Errors in DNA replication and DNA repair are a major source of
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mutations in our cells - CORRECT ANSWERS ✔✔a. Most of the
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inherited changes in our DNA arise because of exposure to
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extracellular mutagens, including sources of chemical mutagens |\ |\ |\ |\ |\ |\




2. With reference to DNA repair, which of the following is false?
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a. Crosslinking of bases on opposite DNA strands is especially
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problematic for cells because it presents and obstacle to DNA |\ |\ |\ |\ |\ |\ |\ |\ |\ |\


replication and the replication fork is stalled |\ |\ |\ |\ |\ |\




b. Double strand DNA breaks are a challenge for cells because if
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repair is not affected immediately the ends can drift apart quickly
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making correct repair impossible
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,c. Crosslinking of bases on opposite DNA strands can be
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problematic for cells because it may present an obstacle to |\ |\ |\ |\ |\ |\ |\ |\ |\ |\


transcription and the RNA polymerase is stalled |\ |\ |\ |\ |\ |\




d. Repair of double stranded DNA breaks is easier in cells prior to
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DNA replication than after DNA replication has occurred -
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CORRECT ANSWERS ✔✔d. Repair of double stranded DNA breaks
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is easier in cells prior to DNA replication than after DNA
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replication has occurred |\ |\




3. With reference to imprinting disorders, which of the following
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is false?
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a. With the exception of abnormal chromosome segregation,
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imprinting disorders always result from a deletion or inactivating
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mutation within or spanning the imprinted gene cluster
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b. Angelman and prader willi syndrome are very different
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disorders but can be caused by precisely the same large deletion
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at 15q11-q13
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c. About one quarter of individuals with angelman syndrome lack
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a paternal chromosome 15
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d. In some imprinting disorders, disease results from
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inappropriate biallelic expression of a gene - CORRECT ANSWERS |\ |\ |\ |\ |\ |\ |\ |\ |\


✔✔a. With the exception of abnormal chromosome segregation,
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imprinting disorders always result from a deletion or inactivating
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mutation within or spanning the imprinted gene cluster
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4. Which of the following describes the non viral transfer of DNA,
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RNA, and oligonucleotides into human or other animal cells? -
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CORRECT ANSWERS ✔✔Transfection |\ |\




5. Which of the following is an example of prevention treatment?
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, a. Organ transplant
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b. Shunting elevated metabolite into side metabolic pathway
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c. Reduction of susceptibility factor
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d. Bone marrow transplant - CORRECT ANSWERS ✔✔c. Reduction
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of susceptibility factor
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6. Which disorders are more suitable for augmentation therapy?
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a. Disorders in which the pathogenesis involves a positively
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harmful effect. |\




b. Recessive disorders
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c. Disorders that do not involve a deficiency
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d. Dominant disorders - CORRECT ANSWERS ✔✔
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7. Which of the following best describes cytokines?
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a. Proteins released by animal cells that are involved in alerting
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the cellular immune
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system of viral infection of host cells
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b. Chemical messengers that help in intracellular signaling
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c. Any of a class of glycoproteins produced by leukocytes for
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regulating immune |\




responses
d. A chemical substance produced in the body that controls and
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regulates the activity |\ |\




of certain cells or organs - CORRECT ANSWERS ✔✔b. Chemical
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messengers that help in intracellular signaling |\ |\ |\ |\ |\