Exam 2 Review

Question 1

What are formed on the lagging strand during DNA synthesis?

Answer 1

Okazaki fragments

Question 2

An example of correct nucleotide pairing is..

Answer 2

A and T, C and G. Thymine is replaced by Uracil in RNA

Question 3

The two strands of the DNA double helix are held together by

Answer 3

hydrogen bonds between nucleotide bases.

Question 4

DNA replication is started with a(n) __________, which, in most cases, in vivo is a short stretch of ___________.

Answer 4

primer
RNA

Question 5

tRNA is released from the ribosome at the ________ site.

Answer 5

E

Question 6

The codon on the _______ matches with the anticodon on the ________ to direct the addition of the correct amino acid to the growing polypeptide chain.

Answer 6

mRNA
tRNA

Question 7

The structure and function of a protein are determined by its _________ sequence.

Answer 7

amino acid

Question 8

GTP provides energy for

Answer 8

translation

Question 9

DNA-binding proteins interact predominantly within which portion of a double-stranded DNA helix?

Answer 9

major groove

Question 10

In the process of transcription, promoters are specific sequences of _______ that are recognized by _________

Answer 10

DNA
sigma factors

Question 11

Transfer RNA (tRNA) molecules

Answer 11

function to transfer the correct amino acids to the ribosome during translation

Question 12

Each adenine-thymine base pair has _________ hydrogen bonds, while each guanine-cysteine base pair has ______ hydrogen bond(s).

Answer 12

two
three

Question 13

An operon is a useful genetic element, because it

Answer 13

allows coordinated expression of multiple related genes in prokaryotes

Question 14

The flow of biological information begins with

Answer 14

DNA replication

Question 15

In Bacteria, a chromosome can be distinguished from a plasmid, because a chromosome is a genetic element that

Answer 15

encodes for essential functional genes

Question 16

When arginine is added to a culture already growing exponentially in a medium without arginine, what occurs?

Answer 16

Growth continues, but the production of enzymes required for the synthesis of arginine ceases.

Question 17

Which type of regulator(s) specifically binds to operator regions of DNA?

Answer 17

Repressors

Question 18

The lac operon is an example of __________ control in which the presence of an _________ is required for transcription to occur.

Answer 18

negative
inducer

Question 19

Enzyme induction occurs

Answer 19

when the substrate is present

Question 20

In negative control of transcription by the lac operon, how does the presence of an inducer affect transcription?

Answer 20

The inducer prevents the repressor from binding to the operator

Question 21

The function of a kinase is

Answer 21

phosphorylation

Question 22

The promoters of positively controlled operons require activator proteins because

Answer 22

the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter

Question 23

_______ pathways typically rely on _______ proteins to inhibit mRNA synthesis.

Answer 23

anabolic
repressor

Question 24

When more than one operon is under the control of a single regulatory protein, the operons are collectively called a(n)

Answer 24

regulon

Question 25

In catabolic repression, cells always use the least abundant carbon source first. T/F?

Answer 25

False

Question 26

A mutant that has a nutritional requirement for growth is an example of a(n)

Answer 26

auxotroph

Question 27

Consider a mutation in which the change is from UAC to UAU. Both codons specify the amino acid tyrosine. Which type of point mutation is this?

Answer 27

silent mutation

Question 28

Which process allows genetic material to be transferred from a virus-like particle that lacks genes for its own replication?

Answer 28

Gene transfer through a gene transfer agent

Question 29

The mutagens 2-aminopurine and 5-bromouracil are examples of

Answer 29

nucleotide base analogs

Question 30

What method(s) may introduce foreign DNA into a recipient?

Answer 30

Transformation, transduction, and conjugation

Question 31

The uptake of free DNA from the environment is referred to as _________, while the transfer of DNA with cell-to-cell contact is known as _________

Answer 31

transformation conjugation

Question 32

Lysogeny probably carries a strong selective advantage for the host cell because it _____

Answer 32

confers resistance to infection by viruses of the same type

Question 33

Hfr strains of E. coli

Answer 33

have an integrated F factor

Question 34

A deleterious mutation in recA results in

Answer 34

a decrease in homologous recombination

Question 35

What is most similar to lysogeny?

Answer 35

Hfr state

Question 36

The SOS regulatory system is activated by

Answer 36

DNA damage

Question 37

True about competence

Answer 37

It is required for transformation it cannot occur naturally in bacteria it requires special proteins such as a cell wall autolysin