Genetics Exam 3 - Quiz

Question 1

According to Chargaff’s rule, if the DNA of a species contains 20% adenine, what percent of guanine will it contain?

Answer 1

30%

Question 2

The first group of researchers to correctly identify the double-helix structure of DNA were

Answer 2

Watson and Crick

Question 3

Avery, Macleod, and McCarty used the enzyme ____ to remove the proteins from the cell extracts

Answer 3

protease

Question 4

The _____ was/were labeled using the radioisotope 32P in the Hershey-Chase experiments

Answer 4

DNA

Question 5

Select the nitrogenous base found only in RNA

Answer 5

uracil

Question 6

The building blocks of DNA are called

Answer 6

nucleotides

Question 7

Which RNA structural pattern does NOT contain single-stranded regions

Answer 7

multi-branched junction

Question 8

The backbone of the DNA molecule is formed by ___

Answer 8

phosphodiester bonds

Question 9

In a double-helix DNA strand the adenine on one strand forms a hydrogen bond with a(n) ____ on the other strand

Answer 9

thymine

Question 10

Select the feature that is incorrect about this double stranded DNA”

5’ - ATGCCCGGAAC - 3’
5’ - TACGGGCCTTG - 5’

Answer 10

The strand is not antiparallel

Question 11

What is true in both phage lambda and HIV infections

Answer 11

There can be a long latent period where no sign of infection, such as cell death is detectable

Question 12

A bacteriophage that is physically integrated into the host chromosome is called a ___

Answer 12

prophage

Question 13

A ____ frequently integrates into the host genome, forming prophages and utilizing a lysogenic cycle to manufacture new phages

Answer 13

temperate phage

Question 14

Vaccines have been very useful in preventing viral diseaSe. In fact, they have lead to the eradication of smallpox from the world’s human population. Most vaccines result in the host producing antibodies (proteins that bind to specific amino acid sequences) that bind to specific viral proteins. What might be a reason why a vaccine for HIV has been so difficult to develop

Answer 14

the high mutation rate of HIV

Question 15

Which virus uses reverse transcriptase in its reporductive cycle

Answer 15

HIV

Question 16

You perform an experiment like that performed by Fraenkel-Contrat and Singer on TMV. However, in the first step when the viruses are reconstituted, you decide to add RNase to your HR RNA and wild-type proteins. what will be the content of the newluy made viral proteins after he reconstituted viruses is placed on leaves

Answer 16

No new viral proteins will be made

Question 17

What is the genetic material in the parvovirus

Answer 17

single-stranded DNA

Question 18

What is the genetic material in the T4 bacteriophage

Answer 18

Double-stranded DNA

Question 19

What is a property of emerging viruses

Answer 19

may lead to a significant loss of human life

recent origin

more likely to cause infection compared to other strains

Question 20

If protein was the genetic material of TMV rather than RNA, what would be the result of the Fraekel-Contrat/Singer experiments when using HR proteins and wild-type RNA

Answer 20

HR type lesions, histidine and methionine in the capsid protein

Question 21

How many origins of replication are there in a bacterial chromosome

Answer 21

1

Question 22

where do kinetochores attach to chromosomes

Answer 22

centromeres

Question 23

The majority of the non-repetitive genes in an organism are found in which of the following

Answer 23

unique sequences

Question 24

The DNA of a bacterial cell must be compacted about ____ fold to fit within the confines of the cell

Answer 24

1000

Question 25

The correct order of compaction from least to greateest

Answer 25

naked DNA nucleosome 30nm fiber loop metaphase chromosome

Question 26

You are performing an experiment to identify chromosome territories in a species with 6 pairs of homologous chromosome, plus two sex chromosomes. You use 7 different colored fluorescent molecules (one for each chromosome and one for the sex chromosome) and link each one to a probe that is highly conserved at the centromere of each chromosome in this species. what will be the result of your experiment

Answer 26

The chromosomes will all be marked but you won't be able to tell which chromosomes in which

Question 27

A double stranded stretch of eukaryotic DNA is 250,000 bp long. IF the average linker is about 54 bp how many nucleosomes would be present on this piece of DNA

Answer 27

1250

Question 28

The formation of what structure would be impaired if a cell was lacking CTCF proteins

Answer 28

loop domains

Question 29

Transposons that use an RNA intermediate for transposition are called

Answer 29

retrotransposons

Question 30

A transposon is inserted into the sequence 5' GACTC 3' following simple transposition into the site, what sequences flank the transposon

Answer 30

5' GACTC 3' 5' GACTC 3'

Question 31

In the attachment of a nucleotide to a DNA strand, the cleavage of the dNTP into deoxyribunucleoside monophosphate and pyrophosphate is ___

Answer 31

exergonic

Question 32

How many DNA polymerase are found in prokaryotes

Answer 32

5

Question 33

What enzyme relaxes supercoiling ahead of the replication fork

Answer 33

topoisomerase

Question 34

What is the purpose of Okazaki fragments

Answer 34

To allow DNA to be synthesized in the 5' to 3' direction on the lagging strand

Question 35

How many origins of replication does a bacterial chromosome contain?

Answer 35

1

Question 36

In yeast, which of the following is similar to the oriC region of prokaryotes

Answer 36

ARS elements

Question 37

If eukaryotic cells evolved such that lagging strand DNA synthesis could occur continuously (without the use of Okazaki fragments), what enzyme would likely no longer be needed for DNA replication?

Answer 37

flap endonuclease

Question 38

What process does the Holliday model help explain

Answer 38

recombination between homologous chromosomes

Question 39

You have isolated what appears to be alien DNA. While studying its replication, you performed the exact experiment Meselson and Stahl did. After three generations, the DNA is subjected to a CsCl gradient and only one band appears. What type of replication does this DNA undergo?

Answer 39

dispersive

Question 40

Which describes the mechanism of DNA replication in which the newly made double-stranded DNA contains one parental strand and one daughter starnd?

Answer 40

semiconservative

Question 41

What is the name of the site in eukaryotic DNA where general transcription factors associate?

Answer 41

promoter

Question 42

Following transcription, the RNA has complementary sequence to

Answer 42

teh template strand of dna

Question 43

In eukaryotic organisms, what process is important for the initiation of translation

Answer 43

5' capping

Question 44

What enables the splicing of group I and II introns

Answer 44

ribozymes

Question 45

In eukaryotic organisms, what RNA modification is important for mRNA stability

Answer 45

3' polyA tailing

Question 46

Which subunit of the prokaryotic RNA polymerase carries out catalytic synthesis of RNA?

Answer 46

beta

Question 47

Both the rho-dependent and rho-independent mechanisms of termination

Answer 47

involve the formation of a stem-loop structure

Question 48

In eukaryotic organisms, what protein allows RNA polymerase II to interact with transcription factors bound to enhancers or silencers

Answer 48

mediator

Question 49

A mutation occurs in one of the general transcription factors necessary for eukaryotic transcription. A pre-initation complex forms, but the open complex does not form. Further, TFIIB, TFIIE, and TFIIIH are not releaSed from the DNA. The mutation is most likely in which general transcription factor

Answer 49

TFIIH

Question 50

What region in eukaryotic genes cotnains the majority of regualtory elements

Answer 50

-50 to -100