Which of the following statements about restriction nucleases is false?
(a) A reproducible set of DNA fragments will be produced every time a restriction nuclease digests a known piece of DNA.
(b) Restriction nucleases recognize specific sequences on single-stranded DNA.
(c) Some bacteria use restriction nucleases as protection from foreign DNA.
(d) Some restriction nucleases cut in a staggered fashion, leaving short, single-stranded regions of DNA at the ends of the cut molecule.
(b) Restriction nucleases cleave double-stranded DNA.
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Which of the following diseases is associated with faulty DNA repair mechanisms?
A. Alzheimer's disease B. diabetes C. xeroderma pigmentosum D. diabetes and xeroderma pigmentosum E. Alzheimer's disease and diabetes
At the pH of most bodily fluids, which functional group will lose a proton and which functional group will accept a proton?
A. sulfhydryl; carbonyl B. amino; carboxyl C. carbonyl; Hydroxyl D. carboxyl; amino E. Hydroxyl; amino
In terms of epigenetics, how the promoter would be described for a gene that is not expressed in lung tissue but is expressed in heart tissue?
A) The promoters should appear the same in both types of cells, but the mRNA produced would be hypermethylated more in lung cells compared to heart cells. B) In lung cells, the guanines in the promoter would be hypomethylated, but would be hypermethylated in heart cells. C) In lung cells, the cytosines of the promoter would be hypomethylated, and would be hypermethylated in heart cells. D) In lung cells, the cytosines of the promoter would be hypermethylated, and would be hypomethylated in heart cells. E) In lung cells, the guanines in the promoter would be hypermethylated, and would be hypomethylated in heart cells.
Pseudomonas aeruginosa is a common pathogen that infects the airways of patients with cystic fibrosis. It does not grow in the absence of oxygen. The bacterium is probably which of the following?
A. an aerotolerant anaerobe B. an obligate aerobe C. an obligate anaerobe D. a facultative anaerobe