Quiz 2

Question 1

The bacterial chromosome is

Answer 1

both circular and found in a nucleoid

Question 2

The function of PCNA is

Answer 2

to work as a sliding clamp

Question 3

Which of the following relationships about nucleotide composition in DNA is TRUE?

Answer 3

C+A=G+T

Question 4

The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is

Answer 4

transformation

Question 5

Beginning with the simplest level of structure, which order of organization of genetic material is CORRECT?

Answer 5

nucleotide, DNA, gene, chromosome, genome

Question 6

Why are the complementary base pairing rules so important when a cell needs to copy its DNA?

Answer 6

As long as there is one strand, a copy can be made by following the pairing rules.

Question 7

The enzymes that can proofread replicating DNA, detect incorrect bases, excise them and correctly replace them are

Answer 7

DNA polymerases

Question 8

Which protein influences the ability of RNA polymerase to transcribe genes?

Answer 8

transcription factors

Question 9

Which of the following would occur if a cell’s splicesomes were mutated so they no longer functioned normally?

Answer 9

Introns would remain in the mature mRNA.

Question 10

Which of the following statements is TRUE about protein synthesis in prokaryotes?

Answer 10

Translation can begin while transcription is still in progress.

Question 11

Ribozyme is an

Answer 11

RNA with enzymatic activity

Question 12

Transcription begins near a site in the DNA called the ________, while the terminator specifies the end of transcription.

Answer 12

promoter

Question 13

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the

Answer 13

bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.

Question 14

New antibiotic is developed that interferes with the way tRNA fits into bacterial ribosomes. How would this kill?

Answer 14

The bacteria would be unable to produce necessary enzymes to carry out basic metabolism.

Question 15

Which of the following proteins is involved in synthesizing messenger RNA in eukaryotes?

Answer 15

RNA polymerase II

Question 16

Analysis of DNA fragments in gel electrophoresis involves

Answer 16

Larger fragments move slowly and remain closer to the wells

DNA has an overall negative charge and moves to the positive pole

DNA fragments are stained with fluorescent dye ethidium bromide to see them

An electric current through the gel causes DNA fragments to migrate

Question 17

Which choice is an example of “recombinant DNA”?

Answer 17

A bacterial plasmid combined with a human gene

Question 18

How does a bacterial cell protect its own DNA from restriction enzymes?

Answer 18

by adding methyl groups to adenines and cytosines

Question 19

You have a small gene that you wish replicated by PCR. After 3 replication cycles, how many double-stranded DNA molecules do you have?

Answer 19

8

Question 20

A small amount of DNA is collected from a crime scene. However, the amount of DNA collected is insufficient to perform the necessary experiments to link a suspect to the crime. What method could be utilized to increase the amount of DNA?

Answer 20

polymerase chain reaction (PCR

Question 21

Which of the following is an advantage of cDNA libraries?

Answer 21

cDNA lacks introns and reflects all the genes expressed by a particular tissue or organism.

Question 22

A student wishes to clone a sequence of DNA of ~200 kb. Which vector would be appropriate?

Answer 22

A BAC

Question 23

To carry out hybridization, why is DNA transferred from a gel to a nitrocellulose paper?

Answer 23

to attach the DNA fragments to a permanent substrate

Question 24

For PCR, DNA is denatured at

Answer 24

95 C

Question 25

Which of the following is TRUE regarding the step in gene cloning when bacterial cells take up recombinant vector?

Answer 25

The cell is treated with agents that render it permeable to the plasmid.

Question 26

When a/n _____________________ binds to the repressor, then the repressor binds to the operator.

Answer 26

co-repressor

Question 27

While synthesizing DNA, the polymerase moves along the parental strand in ______________ direction.

Answer 27

3’ to 5’

Question 28

The ___________________ recognizes a stop codon at the A site of the ribosome.

Answer 28

release factor

Question 29

Enzymes called __________________________ relieve torsional stress that develops in cellular DNA molecules during replication and other processes.

Answer 29

topoisomerases

Question 30

The temperature at which half the bases in a double-stranded DNA sample have denatured is denoted as

Answer 30

Tm