Reference no: EM133292848
Questions
1. The biological role of restriction enzymes is to.
a. degrade foreign DNA that enters a bacterium.
b. restrict the damage to DNA by ultraviolet light.
c. restrict the size of DNA in certain bacteria.
d. make bacteria resistant to antibiotics.
e. aid recombinant DNA research.
2. Certain restriction enzymes produce cohesive (sticky) ends. This means that they:
a. stick tightly to the ends of the DNA they have cut.
b. make ends that can anneal to cohesive ends generated by any other restriction enzyme.
c. cut both DNA strands at the same base pair.
d. make a staggered double-strand cut, leaving ends with a few nucleotides of single-stranded DNA protruding.
e. cut in regions of high GC content, leaving ends that can form more hydrogen bonds than ends of high AT content.
3. The PCR reaction mixture does NOT include:
a. DNA ligase.
b. all four deoxynucleoside triphosphates.
c. DNA containing the sequence to be amplified.
d. heat-stable DNA polymerase.
e. oligonucleotide primer(s).
4. While working in the laboratory, you have been provided a sample of DNA from an unknown bacteria. Adenine makes up 32% of the total bases. What relative proportions of adenine, guanine, thymine, and cytosine would you expect to find in the DNA sample? Assume that the DNA molecules are double-stranded.
a. 32% A, 32% T, 18% G, 18% C
b. 32% A, 18% T, 18% G, 32% C
c. 32% A, 64% T, 36% G, 36% C
d. 32% A, 32% T, 64% G, 64% C
e. 32% A, 18% T, 33% G, 18% C
5. You are working with two unknown species of bacteria, #1 and #2.
Bacteria species #1 contains 32% (Adenine).
Bacteria species #2 contains 15% (Adenine).
Both DNA molecules are double-stranded. Which species is most likely a thermophilic bacterium?
a. Species #1
b. Species #2
6. In the Watson-Crick model of DNA structure (now called B-form DNA):
a. a purine in one strand always hydrogen bonds with a purine in the other strand.
b. the 5' ends of both strands are at one end of the double helix.
c. the nitrogenous bases occupy the interior of the double helix.
d. A-T pairs share three hydrogen bonds.
e. G-C pairs share two hydrogen bonds.
7. When cloning a gene into a plasmid, which enzyme would you use to covalently attach the gene to the plasmid DNA?
a. DNA polymerase
b. exonuclease III
c. alkaline phosphatase
d. a restriction endonuclease
e. DNA Ligase
8. What is a polylinker?
a. a method of getting DNA into a cell
b. a type of cloning vector
c. an enzyme that joins DNA molecules together
d. a DNA fragment with multiple recognition sequences for restriction endonucleases
e. a type of expression vector
9. Which protein does NOT contribute to the octameric histone core?
a. H2B
b. H2A
c. H4
d. H1
e. H3