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Genetics Essentials
Chapters 8-11
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1

After sigma factor guides the RNA polymerase to the correct promoter site, it:

dissociates from the core enzyme

2

The end of an RNA from a bacterial gene is likely to contain

Inverted repeats and a string of U’s

3

Hershey and Chase differentiated between DNA and protein by:

labeling the DNA with 32Phosphorous, proteins with 35Sulfur

4

Contains a guide RNA used as a template

Telomerase

5

Maintains the single-strand form of DNA

SSB

6

Actually synthesizes RNA, not DNA

Primase

7

Is often overactive in cancer cells

Telomerase

8

Coordinate replication requires two

DNA Pol III

9

Opens the double helix for replication machinery

Helicase

10

After several generations of labelling in 15N media, Meselson and Stahl switched to 14N media for one generation. The DNA extracted
after one generation in 14N media was centrifuged in a cesium gradient. The DNA formed a single band with a density somewhere between
DNA grown in 15N media and DNA grown in 14N media. This data is consistent with:

semiconservative and dispersive replication

11

For double-stranded DNA, which of the following base ratios usually does not equal 1

A+T)/(G+C)

12

The form of DNA normally found in our cells is

B

13

The function of DNA ligase is to

Catalyze the formation of covalent bonds between adjacent 5'-P and 3'-OH termini

14

The pyrimidine bases are

Thymine and cytosine

15

Acts in a distance and orientation independent fashion

enhancer

16

Produces large quantities of a few large polymers

RNA Polymerase I

17

upstream elements

CAAT box or GC box

18

Makes tRNA

RNA Polymerase III

19

a protein which binds to TATA boxes

TF IID

20

produces mRNA

unique DNA

21

a protein shaped like an RNA

RF I

22

Required for translocation of ribosome

EF-Tu

23

tRNA entry site

A site

24

ribosomal RNA genes

middle repetitive DNA

25

The correct order of activity in replication is

helicase, SSB, primase, Pol III, Pol I, ligase

26

Which of these RNA sequences could form a hairpin also called a stem loop?

5′ GGGGTTTTCCCC 3′

27

By measuring the UV-melting curves for the DNA of two different organisms (A and B) in the same solution and
concentration, we have found the following melting temperatures (Tm): Tm(A)= 70.2 C and Tm(B)=75.6 C. Which of
the following is correct

B has more guanine than A

28

Okazaki fragments

lagging strand

29

DNA primase

RNA primer synthesis

30

DNA gyrase

supercoil removal

31

continuous synthesis

leading strand

32

DNA proofreading

3′ -->5′ exonuclease activity

33

heteroduplex DNA

strand invasion

34

DNA ligase

phosphodiester bonds at DNA nicks

35

theta replication

strand invasion

36

DNA synthesis

5’ -->3’ polymerase activity

37

Primer removal

5’--> 3’ exonuclease activity

38

Which is a mechanism that allows a single gene to encode more than one polypeptide?

Alternative RNA splicing

39

If the sequence of an RNA molecule is 5’-GGCAUCGACG-3’, what is the sequence of the template strand of
DNA?

5’-CGTCGATGCC-3’

40

An in vitro transcription system transcribes a bacterial gene but terminates inefficiently. What is one possible
problem?

Rho factor has not been added

41

Discontinuous replication

Occurs on the DNA strand synthesized overall in the 3' to 5' direction. Results in the formation of Okazaki fragments

42

Termination of transcription in prokaryotes is carried out in part by a

stem loop or hairpin structure

43

The P site in the ribosome is named for

Peptidyl

44

The signal for polyadenylation of the mRNA is

AAUAAA

45

Which of the following statements regarding gene expression is true?

Messenger RNA is translated in the 5' to 3' direction

46

The genetic code is said to be redundant because

Several codons direct the insertion of the same amino acid into a polypeptide chain

47

Which of the following is not present as a dimer in a histone core

H1

48

Interacts with A site when ribosome is on a stop codon

RFII

49

helps assemble large and small ribosomal subunits

IF2

50

carries the anticodon

tRNA

51

charges the tRNA

aminoacyl synthetase

52

Participates in addition of an amino acid to a growing polypeptide chain

EF-Tu

53

Which level of protein structure includes alpha helix and beta pleated sheet

secondary

54

Which of the following is not different between eukaryotic and prokaryotic transcription a) Splicing b) 5' capping c) poly-adenylation d) termination
e) all are different

e) all are different

55

Which one of the following is not a stop codon

UGG

56

A DNA molecule of 500 bp will have approximately how many turns?

50

57

Synthetic mRNAs were used to predict the genetic code. Which of the following is not true

repeats of three nucleotides produce a polymer with a three amino acid repeat unit

58

The corepressor of tryptophan biosynthesis is

Tryptophan

59

Which feature of gene regulation is present only in eukaryotes

Alternative splicing

60

Insertion sequences (IS) inserted in the genome are flanked by:

Direct genomic repeats and inverted sequence elements

61

Which feature of gene regulation is present only in prokaryotic genomes?

Attenuators

62

Which of the Following is true for recombination?

Inversions interfere with recombination, reciprocal translocations with forming gametes with the correct chromosome balance

63

Which level of protein structure deals with just the sequence of amino acids

primary

64

the Meselson Stahl experiment differentiating the modes of replication by labeling with different forms of nitrogen and spinning in a
cesium gradient, how many rounds of replication were needed to determine if the following modes of replication were not used in E. coli?

two rounds of replication for dispersive; one round of replication for conservative

65

A bacterium has positively supercoiled DNA. This is likely because

The bacteria normally grow in high temperature conditions

66

A bacterium inherits a mutation that renders its gyrase enzyme nonfunctional. What phenotype would you expect to see in this bacterium?

The cell would accumulate broken DNA because overwinding cannot be corrected, so the cell will be unable to replicate and will die.

67

What is meant by the "beads on a string" model of chromatin?

The beads are the nucleosomes, and the string is the linker DNA

68

A cell can form beads on a string chromatin, but not solenoid fibers. Which molecule has likely been removed or mutated in this cell?

H1

69

How does the eukaryotic initiation complex locate the true start codon?

The true start codon is the first ATG encountered downstream of the Kozak sequence.

70

You want to design a drug that prevents transcription of mRNAs but does not affect transcription of other RNAs. What enzyme would you target?

RNA polymerase II

71

Which type of RNA is translated within a cell?

mRNA

72

In 1928, Griffith found that injecting which strains of Pneumococcus caused the mouse to die?

heat-killed type SIII and living type RII

73

Which of the following are classified as pyrimidines?

thymine and cytosine

74

What enzyme(s) is/are responsible for removal of RNA primers and joining of Okazaki fragments?

DNA polymerase I and DNA ligase

75

Which one of the following statements is not true for all E. coli DNA polymerases?

They possess 5'to 3' exonuclease activity.

76

Which statement is true regarding negative supercoiled DNA?

Negative supercoiled DNA is under-rotated and allows for easier strand separation during replication and transcription

77

What would Avery, Macleod, and McCarty have concluded if their results had been that only RNAse treatment of the heat-killed bacteria prevented transformation of genetic virulence?

RNA is the genetic material

78

Okazaki fragments are found associated with

lagging strand

79

After the first round of replication, Meselson and Stahl saw only one DNA band of density intermediate to DNA containing only 15N or 14N. After this observation, which hypothesis for DNA replication could be eliminated ?

conservative

80

DNA synthesis in eukaryotes is?

semi-conservative

81

According to Chargaff’s rules, if a genome is 30% adenine, then what percentage of the genome should be guanine

C.20%