MICRO TEST 4 ( CHAPTER 7 MICROBIAL GENETICS)

Question 1

Which of the following is the most likely number of base pairs in a bacterial chromosome?

Answer 1

4,000,000

Question 2

Which of the following is a true statement concerning the bacterial chromosome?

Answer 2

They are located in the cytosol

Question 3

A plasmid is

Answer 3

Extrachromosomal DNA

Question 4

Which of the following forms ionic bonds with eukaryotic DNA and stabilizes it?

Answer 4

histone

Question 5

Nucleotides used in the replication of DNA.

Answer 5

All of these

Question 6

Which of the following molecules functions as a “proofreader” for a newly replicated strand of DNA?

Answer 6

DNA polymerase III

Question 7

The addition of -CH to a cytosine molecule after DNA replication is called —

Answer 7

Methylation

Question 8

In translation, the binding site through which the tRNA molecules leave is called the —

Answer 8

E site

Question 9

The Ames test

Answer 9

uses auxotrophs and liver extract to reveal potential mutagens

Question 10

Which of the following methods of DNA repair involves enzymes that recognize and correct nucleotide errors in unmethylated strands of DNA?

Answer 10

mismatch repair

Question 11

Which of the following is not a mechanism of natural genetic transfer and recombination?

Answer 11

transformation

Question 12

Cells that have the ability to take up DNA from their environment are said to be —.

Answer 12

competent

Question 13

Which of the following statements is true?

Answer 13

Conjugation requires a sex pilus extending from the surface of a cell.

Question 14

Which of the following are called “jumping genes”?

Answer 14

transposons

Question 15

This process is —

Answer 15

horizontal gene transfer

Question 16

Which of the following is part of each molecule of mRNA?

Answer 16

codon

Question 17

A nucleotide is composed of _

Answer 17

All of these.

Question 18

in DNA, adenine forms ___ hydrogen bonds with__?

Answer 18

two; thymine

Question 19

A sequence of nucleotides formed during replication of the lagging DNA strand is _

Answer 19

an Okazaki fragment

Question 20

Which of the following is not part of an operon?

Answer 20

origin

Question 21

Repressible operons are important in regulating prokaryotic

Answer 21

RNA transcription

Question 22

Transcription produces

Answer 22

RNA molecules

Question 23

Ligase plays a major role in

Answer 23

lagging strand replication

Question 24

Before mutations can affect a population permanently, they must be

Answer 24

4. All of these.

Question 25

The trp operon is repressible. This means it is usually___and directly controlled by___.

Answer 25

Active; repressor