Ch. 20 Concept Check & Comprehension Questions

Question 1

What may be used as a vector in a gene-cloning experiment?

Answer 1

Plasmid and virus

Question 2

The restriction enzymes used in gene-cloning experiments ___, which generates sticky ends that can ___.

Answer 2

Cut the DNA, hydrogen bond with complementary sticky ends

Question 3

What is the proper order of steps in a gene-cloning experiment involving vectors?

Answer 3

• incubate the chromosomal DNA and the vector DNA with a restriction enzyme
• mix the chromosomal DNA and vector DNA together
• add DNA ligase
• introduce the DNA into living cells

Question 4

The function of reverse transcriptase is to..

Answer 4

Copy RNA into DNA

Question 5

A collection of recombinant vectors that contain fragments of chromosomal DNA is called..

Answer 5

A genomic library

Question 6

The action of a restriction enzyme and the production of recombinant DNA.

Prior to the action of DNA ligase, how many hydrogen bonds are holding these two DNA fragments together?

Answer 6

Eight

Question 7

The steps in gene cloning.

Explain the role of the selectable marker gene in this experiment.

Answer 7

In this experiment, the selectable marker gene selects for the growth of bacteria that have taken up a plasmid.

Question 8

Synthesis of cDNA.

Explain the meaning of the term reverse transcriptase.

Answer 8

Reverse transcriptase refers to the idea that this enzyme catalyzes then opposite of transcription. It uses an RNA template to make DNA, whereas during transcription a DNA template is used to make RNA.