Question 1

Denaturation of DNA is a necessary step in Southern blotting procedure because it separates double stranded DNA into single stranded DNA.

Accepted Answer

A) True 
 B)False

Question 2

A student in a biology laboratory designs oligonucleotide primers to carry out the polymerase chain reaction. However when ordering the sequences, she reverses the 3' and 5' ends. The vendor synthesizes the sequences as ordered and returns them to the student. Will they produce an amplified product? Please explain your answer.

Accepted Answer

They will not work. In fact, they will n

Question 3

In addition to introducing mutations in a gene, DNA editing by means of CRISPR can also correct mutations in a gene.

Accepted Answer

A) True 
 B)False

Question 4

What is the benefit of using Taq polymerase in PCR?

Accepted Answer

A) Because it is taken from bacteria that live in high temperatures, it doesn't have a proofreading function. 
B) Because it is taken from bacteria, this enzyme works much more efficiently than other types of DNA polymerase. 
C) Because it is taken from bacteria that live in high temperatures, it stays active during denaturation steps of the reaction 
D) Because it is taken from bacteria, it makes fewer mistakes. 
E) None of the other answer options is correct. 
A) Because it is taken from bacteria that live in high temperatures, it doesn't have a proofreading function. 
B) Because it is taken from bacteria, this enzyme works much more efficiently than other types of DNA polymerase. 
C) Because it is taken from bacteria that live in high temperatures, it stays active during denaturation steps of the reaction 
D) Because it is taken from bacteria, it makes fewer mistakes. 
E) None of the other answer options is correct.

Question 5

The fact that DNA replication occurs in virtually the same way in all organisms reflects:

Accepted Answer

A) its origin early in the history of life. 
B) its multiple origins in different lineages of organisms. 
C) the laws of thermodynamics. 
D) the fact that mutations are generally harmful. 
E) the universal genetic code. 
A) its origin early in the history of life. 
B) its multiple origins in different lineages of organisms. 
C) the laws of thermodynamics. 
D) the fact that mutations are generally harmful. 
E) the universal genetic code.

Question 6

Which of the following statements is TRUE regarding DNA replication?

Accepted Answer

A) Only the lagging strand gets shortened during replication. 
B) Only the leading strand gets shortened during replication. 
C) Both strands get shortened at the same end during replication. 
D) Both strands get shortened at opposite ends during replication. 
E) Only the lagging strand gets shortened after every other round of replication. 
A) Only the lagging strand gets shortened during replication. 
B) Only the leading strand gets shortened during replication. 
C) Both strands get shortened at the same end during replication. 
D) Both strands get shortened at opposite ends during replication. 
E) Only the lagging strand gets shortened after every other round of replication.

Question 7

Forensic technicians unearth a skeleton from a shallow grave. They extract a tiny amount of DNA from the pulp found in the teeth. How could they obtain sufficient DNA for an analysis of the victim's genes?

Accepted Answer

A) subject the DNA to gel electrophoresis 
B) use a nucleic acid probe 
C) subject the specimen to amniocentesis 
D) use the polymerase chain reaction 
E) subject the DNA to restriction enzymes 
A) subject the DNA to gel electrophoresis 
B) use a nucleic acid probe 
C) subject the specimen to amniocentesis 
D) use the polymerase chain reaction 
E) subject the DNA to restriction enzymes

Question 8

Which of the following enzymes is necessary to produce recombinant DNA?

Accepted Answer

A) helicase 
B) Taq polymerase 
C) primase 
D) DNA ligase 
E) topoisomerase 
A) helicase 
B) Taq polymerase 
C) primase 
D) DNA ligase 
E) topoisomerase

Question 9

One of the first uses of DNA renaturation (hybridization) was to determine the degree of similarity in DNA between different pairs of species; this technique provides a measure of how closely the species are related evolutionarily. In renaturation studies, the genetic similarity between two samples is measured by determining the:

Accepted Answer

A) number and locations of bands on an electrophoresis gel. 
B) number of restriction sites in each of the samples. 
C) temperature at which the two samples form duplexes. 
D) rate at which PCR amplifies the two samples. 
E) nucleotide sequences of each sample. 
A) number and locations of bands on an electrophoresis gel. 
B) number of restriction sites in each of the samples. 
C) temperature at which the two samples form duplexes. 
D) rate at which PCR amplifies the two samples. 
E) nucleotide sequences of each sample.

Question 10

Gel electrophoresis can distinguish between the _____ of different DNA fragments.

Accepted Answer

A) sequences 
B) charge 
C) sizes 
A) sequences 
B) charge 
C) sizes

Question 11

The oligonucleotide primers used in the polymerase chain reaction are typically 20-30 nucleotides in length or longer; however, for purposes of this problem let's assume that six nucleotides is long enough. You wish to amplify the fragment shown below (the raised dots indicate several kilobases of DNA sequence not shown) and decide to design primers corresponding to the regions that are shown in bold. What primer sequences would you use? 5 '-TCAAACTTGCATGTG $ \cdots $ GAGCCATGTGGCACAAA-3'
3'-AGTTTGAACGTACAG $ \cdots $ CTCGGTACACCGTGTTT-5 '

Accepted Answer

A) 5'-GCAAGT-3' and 5'-TGCCAC-3' 
B) 5'-ACTTGC-3' and 5'-GTGGCA-3' 
C) 5'-GCAAGT-3' and 5'-GTGGCA-3' 
D) 5'-ACTTGC-3' and 5'-TGCCAC-3' 
A) 5'-GCAAGT-3' and 5'-TGCCAC-3' 
B) 5'-ACTTGC-3' and 5'-GTGGCA-3' 
C) 5'-GCAAGT-3' and 5'-GTGGCA-3' 
D) 5'-ACTTGC-3' and 5'-TGCCAC-3'

Question 12

As a piece of linear DNA is replicated, the leading strand will have _____ RNA primer(s) and the lagging strand will have _____ RNA primer(s).

Accepted Answer

A) one; one 
B) one; two 
C) one; many 
D) many; one 
E) many; many 
A) one; one 
B) one; two 
C) one; many 
D) many; one 
E) many; many

Question 13

_____ moves outward from the origin of replication and breaks hydrogen bonds between DNA nucleotides.

Accepted Answer

A) RNA primase 
B) Helicase 
C) Topoisomerase II 
D) DNA polymerase 
A) RNA primase 
B) Helicase 
C) Topoisomerase II 
D) DNA polymerase

Question 14

DNA replication of small circular molecules usually starts at a single origin of replication and proceeds bidirectionally (that is, with two replication forks proceeding in opposite directions from the origin of replication). How would the time required for replication be affected if replication of such a molecule were unidirectional rather than bidirectional?

Accepted Answer

The time required for replicat

Question 15

A cell with a defect in the proofreading function of DNA polymerase is observed to have a rate of incorporation of incorrect bases into newly synthesized DNA that is 100 times greater than a cell with a nondefective, normal DNA polymerase. Estimate from this number what fraction of incorrect nucleotide incorporations are corrected by the proofreading function of DNA polymerase in the cell with normal DNA polymerase.

Accepted Answer

A) 0)9 percent 
B) 9)0 percent 
C) 99.0 percent 
D) 99.9 percent 
A) 0)9 percent 
B) 9)0 percent 
C) 99.0 percent 
D) 99.9 percent

Question 16

Restriction enzymes recognize certain DNA sequences and:

Accepted Answer

A) cut straight through both strands of DNA. 
B) cut through the DNA, leaving some overhang at both ends. 
C) will alternate between cutting straight through both strands of DNA and leaving some overhang at both ends. 
D) some of them will cut straight through, while others will leave an overhang at both ends of the cut. 
A) cut straight through both strands of DNA. 
B) cut through the DNA, leaving some overhang at both ends. 
C) will alternate between cutting straight through both strands of DNA and leaving some overhang at both ends. 
D) some of them will cut straight through, while others will leave an overhang at both ends of the cut.

Question 17

The enzyme responsible for replacing RNA primers with DNA is a type of:

Accepted Answer

A) DNA polymerase. 
B) helicase. 
C) topoisomerase II. 
D) DNA ligase. 
E) DNA replicase. 
A) DNA polymerase. 
B) helicase. 
C) topoisomerase II. 
D) DNA ligase. 
E) DNA replicase.

Question 18

Using PCR, a student wants to amplify a sequence of known DNA from a genomic DNA sample. The two primers are both designed to pair with sequences that have a 40% GC content. Using a particular set of denaturation temperatures, annealing temperatures, and extension temperatures, the experiment does not produce the expected single DNA fragment of a single known size, but instead a set of fragments of varied sizes. Which of the following could account for these results?

Accepted Answer

A) The annealing temperature was too low so that the primers can bind with multiple genomic sequences that contain some mismatched bases. 
B) The denaturation temperature was too high so that the primers can bind with each other as well as with multiple genomic sites containing mismatches. 
C) The extension temperature was too low so that many fragments were terminated before the full fragment was replicated. 
A) The annealing temperature was too low so that the primers can bind with multiple genomic sequences that contain some mismatched bases. 
B) The denaturation temperature was too high so that the primers can bind with each other as well as with multiple genomic sites containing mismatches. 
C) The extension temperature was too low so that many fragments were terminated before the full fragment was replicated.

Question 19

Mitochondria contain their own double-stranded, circular DNA and replicate on their own. Why don't they suffer the same consequences as our cells in terms of limited division?

Accepted Answer

A) Because they have high telomerase activity. 
B) Shortening of the DNA is only a problem with nuclear DNA; shortening of mitochondrial DNA isn't catastrophic. 
C) Because mitochondrial DNA is circular, it doesn't shorten when it replicates. 
D) Since mitochondrial DNA only contains a few genes, it can last a lot longer. 
E) Because they have high telomerase activity and their DNA is circular and so doesn't shorten in replication. 
A) Because they have high telomerase activity. 
B) Shortening of the DNA is only a problem with nuclear DNA; shortening of mitochondrial DNA isn't catastrophic. 
C) Because mitochondrial DNA is circular, it doesn't shorten when it replicates. 
D) Since mitochondrial DNA only contains a few genes, it can last a lot longer. 
E) Because they have high telomerase activity and their DNA is circular and so doesn't shorten in replication.

Question 20

The enzyme that catalyzes the addition of new nucleotides to a growing DNA strand is:

Accepted Answer

A) DNA polymerase. 
B) helicase. 
C) topoisomerase II. 
D) DNA ligase. 
E) DNA replicase. 
A) DNA polymerase. 
B) helicase. 
C) topoisomerase II. 
D) DNA ligase. 
E) DNA replicase.

Exam 12: Dna Replication and Manipulation

Denaturation of DNA is a necessary step in Southern blotting procedure because it separates double stranded DNA into single stranded DNA.

In addition to introducing mutations in a gene, DNA editing by means of CRISPR can also correct mutations in a gene.

What is the benefit of using Taq polymerase in PCR?

The fact that DNA replication occurs in virtually the same way in all organisms reflects:

Which of the following statements is TRUE regarding DNA replication?

Forensic technicians unearth a skeleton from a shallow grave. They extract a tiny amount of DNA from the pulp found in the teeth. How could they obtain sufficient DNA for an analysis of the victim's genes?

Which of the following enzymes is necessary to produce recombinant DNA?

Gel electrophoresis can distinguish between the _____ of different DNA fragments.

As a piece of linear DNA is replicated, the leading strand will have _____ RNA primer(s) and the lagging strand will have _____ RNA primer(s).

_____ moves outward from the origin of replication and breaks hydrogen bonds between DNA nucleotides.

Restriction enzymes recognize certain DNA sequences and:

The enzyme responsible for replacing RNA primers with DNA is a type of:

Mitochondria contain their own double-stranded, circular DNA and replicate on their own. Why don't they suffer the same consequences as our cells in terms of limited division?

The enzyme that catalyzes the addition of new nucleotides to a growing DNA strand is:

Life: Chemical, Cellular, and Evolutionary Foundations

The Molecules of Life

Nucleic Acids and Transcription

Translation and Protein Structure

Organizing Principles: Lipids, Membranes, and Cell Compartments

Making Life Work: Capturing and Using Energy

Cellular Respiration: Harvesting Energy From Carbohydrates and Other Fuel Molecules

Photosynthesis: Using Sunlight to Build Carbohydrates

Cell Signaling

Cell and Tissue Architecture: Cytoskeleton, Cell Junctions, and Extracellular Matrix

Cell Division: Variations, Regulation, and Cancer

Genomes

Mutation and Dna Repair

Genetic Variation

Mendelian Inheritance

Inheritance of Sex Chromosomes, Linked Genes, and Organelles

The Genetic and Environmental Basis of Complex Traits

Genetic and Epigenetic Regulation

Genes and Development

Evolution: How Genotypes and Phenotypes Change Over Time

Species and Speciation

Evolutionary Patterns: Phylogeny and Fossils

Human Origins and Evolution

Cycling Carbon

Bacteria and Archaea

Eukaryotic Cells: Origins and Diversity

Being Multicellular

Plant Structure and Function: Moving Photosynthesis Onto Land

Plant Reproduction: Finding Mates and Dispersing Young

Plant Growth and Development

Plant Defense: Keeping the World Green

Plant Diversity

Fungi: Structure, Function, and Diversity

Animal Nervous Systems

Animal Sensory Systems and Brain Function

Animal Movement: Muscles and Skeletons

Animal Endocrine Systems

Animal Cardiovascular and Respiratory Systems

Animal Metabolism, Nutrition, and Digestion

Animal Renal Systems: Water and Waste

Animal Reproduction and Development

Animal Immune Systems

Animal Diversity

Animal Behavior

Population Ecology

Species Interactions, Communities, and Ecosystems

Biomes and Global Ecology

The Anthropocene: Humans As a Planetary Force

Filters

As a piece of linear DNA is replicated, the leading strand will have _ RNA primer(s) and the lagging strand will have _ RNA primer(s).