Chapter 18, Genetic Technologies: How Biologists Study Genes and Genomes Video Solutions, Principles of Biology

Problem 1

Restriction enzymes used in most cloning experiments
a. are used to cut DNA into pieces for gene cloning.
b. are produced by bacteria cells to prevent viral infection.
c. produce sticky ends on DNA fragments.
d. all of the above
c. only a and c

Bryan Valdivia

Numerade Educator

01:12

Problem 2

DNA ligase is needed in a cloning experiment
a. to promote hydrogen bonding between sticky ends.
b. to covalently link the backbone of DNA strands.
c. to digest the chromosomal DNA into small pieces.
d. only a and b
e. answers $\mathrm{a}$, $\mathrm{b}$, and $\mathrm{c}$

Christina Sorrentino

Numerade Educator

01:57

Problem 3

Let's suppose you followed the protocols described in Figures $18.2$ and 18.3. Which experiment(s) would you conduct to confirm that a white colony really contained a recombinant vector with an insert?
a. Pick a white bacterial colony and restreak on plates containing X-Gal to confirm that the cells really form white colonies.
b. Pick a white bacterial colony, isolate plasmid DNA, digest the plasmid DNA with a restriction enzyme, and then perform gel electrophoresis with the DNA.
c. Pick a white bacterial colony and test it to see if $\beta$-galactosidase is functional within the bacterial cells.
d. Pick a white bacterial colony and retest it on ampicillincontaining plates to double-check that the cells are really ampicillin resistant.
e. Both $\mathrm{c}$ and $\mathrm{d}$ should be conducted.

Shireen Shah

Numerade Educator

01:15

Problem 4

Why is Taq polymerase used in PCR rather than other DNA polymerases?
a. Taq polymerase is a synthetic enzyme that produces DNA strands at a faster rate than natural polymerases.
b. Taq polymerase is a heat-stable form of DNA polymerase that can function after exposure to the high temperatures necessary for PCR.
c. Taq polymerase is easier to isolate than other DNA polymerases.
d. Taq polymerase is the DNA polymerase commonly produced by most cukaryotic cells.
e. All of the above are correct.

Shireen Shah

Numerade Educator

07:51

Problem 5

Let's suppose you want to clone a gene that has never been analyzed before by DNA sequencing. Which of the following statements do you agree with the most?
a. Do PCR to clone the gene because it is much faster.
b. Do PCR to clone the gene because it is very specific and gives a high yield.
c. You can't do PCR because you can't make forward and reverse primers.
d. Do cloning using a vector because it will give you a higher yield.
e. Do cloning by insertion into a vector because it is easier than PCR.

Norma Kimmel

Numerade Educator