Chapter 20
Biotechnology
Multiple-Choice Questions
Figure 20.1
1) Which enzyme was used to produce the molecule in Figure 20.1?
A) ligase
B) transcriptase
C) a restriction enzyme
D) RNA polymerase
E) DNA polymerase
Answer: C
Topic: Concept 20.1
Skill: Application/Analysis
2) Assume that you are trying to insert a gene into a plasmid. Someone gives you a preparation of genomic DNA that has been cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for
Y, but not for X. Your strategy should be to
A) insert the fragments cut with X directly into the plasmid without cutting the plasmid.
B) cut the plasmid with restriction enzyme X and insert the fragments cut with Y into the plasmid. C) cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme.
D) cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the DNA fragments cut with restriction enzyme X.
E) cut the plasmid with enzyme X and then insert the gene into the plasmid.
Answer: C
Topic: Concept 20.1
Skill: Application/Analysis
3) What is the enzymatic function of restriction enzymes?
A) to add new nucleotides to the growing strand of DNA
B) to join nucleotides during replication
C) to join nucleotides during transcription
1
D) to cleave nucleic acids at specific sites
E) to repair breaks in sugar-phosphate backbones
Answer: D
Topic: Concept 20.1
Skill: Knowledge/Comprehension
4) How does a bacterial cell protect its own DNA from restriction enzymes?
A) adding methyl groups to adenines and cytosines
B) using DNA ligase to seal the bacterial DNA into a closed circle
C) adding histones to protect the double-stranded DNA
D) forming "sticky ends" of bacterial DNA to prevent the enzyme from attaching
E) reinforcing the bacterial DNA structure with covalent