Question 1

DNA proofreading relies upon recognition of correct _______ base pairing by the DNA polymerase complex.

Accepted Answer

The answer of DNA proofreading relies upon recognition of correct...

Question 2

If the enzyme _______ were nonfunctional, the double helix would not be able to unwind and separate into single strands.

Accepted Answer

The answer of If the enzyme _______ were nonfunctional, the...

Question 3

A researcher transfects mammalian cells with a gene of interest.However, expression of the gene will not confer a selectable phenotype.To differentiate between transfected and nontransfected cells in the transfection solution, the researcher should include a gene for a _______.

Accepted Answer

The answer of A researcher transfects mammalian cells with a...

Question 4

Comparison of the genomic sequences of parental and progeny viruses indicated a high level of error in replication.This information suggests that the DNA polymerase replicating the viral DNA lacked a _______ mechanism.

Accepted Answer

The answer of Comparison of the genomic sequences of parental...

Question 5

Bacteria from hot springs greatly helped the development of PCR by

Accepted Answer

Bacteria from hot springs helped in the development of PCR by providing a heat-tolerant DNA polymerase known as Taq polymerase, which can withstand the high temperatures required for DNA denaturation during PCR amplification.

Question 6

A researcher stains various types of cells from the same organism, using a dye that stains in direct proportion to the amount of DNA in the cell.The researcher finds that _______ cells have twice as much DNA in their nuclei as the organism's sperm do.

Accepted Answer

The answer of A researcher stains various types of cells...

Question 7

Based on what you have learned about the experiments conducted by Griffith and Avery and colleagues with bacteria, which of the following would result in transformation of living R cells?

Accepted Answer

The answer of Based on what you have learned about...

Question 8

In addition to identifying the genetic material, the experiments of Avery, MacLeod, and McCarty with different strains of Streptococcus pneumoniae demonstrated that

Accepted Answer

The answer of In addition to identifying the genetic material,...

Question 9

The "P" in "PCR" stands for _______.

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The answer of The "P" in "PCR" stands for _______....

Question 10

Researchers have determined the chemical composition of a molecule that interacts with DNA.To understand how it binds to a DNA molecule, the researchers can utilize _______ to deduce the physical structure of the molecule.

Accepted Answer

The answer of Researchers have determined the chemical composition of...

Question 11

Refer to the chemical formula of dideoxycytidine.  The drug dideoxycytidine, used to treat certain viral infections, is a nucleotide made with 2',3'-dideoxyribose.This sugar lacks -OH groups at both the 2' and the 3' positions.This drug stops the growth of a DNA chain when added to DNA because

Accepted Answer

Dideoxycytidine lacks -OH groups at both the 2' and 3' positions of the sugar, which are necessary for DNA polymerase to add the next nucleotide in the growing DNA chain. Therefore, the drug stops DNA chain growth.

Question 12

Exposure to sunlight induces thymine dimers in the DNA of skin fibroblasts.To protect against cancer development, the cells will use the _______ DNA repair mechanism to repair the damage.

Accepted Answer

The answer of Exposure to sunlight induces thymine dimers in...

Question 13

The enzyme _______ adds short strands of RNA to the lagging strand.

Accepted Answer

The answer of The enzyme _______ adds short strands of...

Question 14

PCR is commonly used in research, forensics, and for the diagnosis of pathogens and genetic diseases.A commercial standardized diagnostic PCR test has been developed that uses one set of primers to amplify a short DNA template.For which of the following scenarios would such a standardized PCR test be most appropriate:

Accepted Answer

A standardized PCR test would be most appropriate for testing for the presence of a specific pathogen, such as Shigella, in a water supply. This is because the test uses one set of primers to amplify a specific DNA template, allowing for highly sensitive and specific detection of the target pathogen. The other options involve either identifying a suspect using hair, testing for general bacterial, fungal, or amoebic contamination, isolating a full gene sequence, or determining the source of a fecal sample, which would require different types of PCR assays or other techniques.

Question 15

If human DNA polymerase $\alpha$ is substituted for Thermus aquaticus DNA polymerase, what will be the effect on the PCR amplification of a template DNA?

Accepted Answer

Human DNA polymerase is not designed to withstand the high temperatures used in PCR cycles, unlike Thermus aquaticus DNA polymerase, which is thermostable. Therefore, substituting it would lead to the enzyme being denatured at the high temperatures, stopping the PCR process after one round.

Question 16

In order to show that DNA in cell extracts is responsible for genetic transformation in Streptococcus pneumoniae, important corroborating evidence should indicate that _______ also destroy transforming activity.

Accepted Answer

The answer of In order to show that DNA in...

Question 17

Mammalian _______ is the eukaryotic equivalent of bacterial transformation.

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The answer of Mammalian _______ is the eukaryotic equivalent of...

Question 18

When an enzyme is able to catalyze multiple reactions each time it binds to its substrate, thereby creating multiple products, it is said to be _______.

Accepted Answer

The answer of When an enzyme is able to catalyze...

Question 19

The enzyme _______ catalyzes the addition of nucleotides to a growing strand of DNA.

Accepted Answer

The answer of The enzyme _______ catalyzes the addition of...

Question 20

What enables the specificity of PCR?

Accepted Answer

The use of particular primers is what enables the specificity of PCR. Primers bind to the specific target sequence and initiate polymerization by the DNA polymerase.

Answer: A 
 A heat-tolerant DNA polymerase is also necessary for PCR as it can withstand the high temperature used to denature DNA, and can extend primers during the annealing step.

Therefore, the best choices are C and A.

Quiz 13: Dna and Its Role in Heredity