Chapter 12 Launchpad

RNA is involved in which cellular processes? - transcription - DNA replication - All of these choices are correct. - translation

All of these choices are correct.

Which reason explains why bacteria can continually divide while they maintain the length of their chromosome? - Because their DNA is circular, it never shortens after replication. - because they are so simple - because they have plasmids - because they only have one chromosome - because DNA replication is much quicker in bacteria than in eukaryotes

Because their DNA is circular, it never shortens after replication

One method for changing the DNA sequence of a gene in its original location in the cell uses a type of technology known as: - CRISPR-Cas9. - microarrays. - PCR-RLFP. - ELISA. - RISK.

CRISPR-Cas9.

What is the result of DNA ligase's action? - DNA translation occurs. - DNA is broken up at specific sites. - DNA is condensed to chromosomes. - DNA fragments are joined together. - DNA transcription occurs.

DNA fragments are joined together.

Which enzyme is necessary to produce recombinant DNA? - primase - Taq polymerase - DNA ligase - helicase - topoisomerase

DNA ligase

Why are primers needed for DNA replication? - DNA polymerase can only add nucleotides to an existing chain. - A tiny amount of RNA is needed to tell the cell where genes are located. - They help with the joining of Okazaki fragments. - The primers help with the proofreading function of DNA polymerase. - They help direct the placement of the telomeres.

DNA polymerase can only add nucleotides to an existing chain.

What procedure could be used after PCR is complete to make certain that the amplification process worked properly and that the correct sequence was amplified? - DNA hybridization - DNA denaturation - None of the answer options is correct. - gel electrophoresis - DNA sequencing

DNA sequencing

What is the difference between PCR and Sanger sequencing with regard to the materials needed to perform these reactions? - DNA polymerase is needed in Sanger sequencing but not in PCR. - Primers are needed in Sanger sequencing but not in PCR. - Primers are needed in PCR but not in Sanger sequencing. - DNA polymerase is needed in PCR but not in Sanger sequencing. - Dideoxynucleotides are needed in Sanger sequencing but not in PCR.

Dideoxynucleotides are needed in Sanger sequencing but not in PCR.

Imagine that a doctor is culturing two types of cells: one from a malignant melanoma and one from a normal skin sample. How would you expect these two cell populations to differ? - Normal skin cells would have telomeres that do not shorten during successive rounds of replication. - Normal skin cells would have active telomerases that constantly replenish and lengthen telomeres. - Malignant melanoma cells would have active telomerases that constantly replenish and lengthen telomeres. - Malignant melanoma cells would have telomeres that shorten during successive rounds of replication. - Malignant melanoma cells would have inactive telomerases, so their telomeres would shorten during successive rounds of replication.

Malignant melanoma cells would have active telomerases that constantly replenish and lengthen telomeres.

Which statement is true regarding origins of replication? - Eukaryotic DNA always has one origin of replication. - None of the answer options is correct. - The replication bubbles associated with different origins of replication never fuse. - Origins of replication are synonymous with replication forks. - Circular DNA always has between 2 and 3 origins of replication.

None of the answer options is correct.

Which statement about the strands of a newly replicated DNA molecule is correct? - One strand is new, and the other is from the original molecule. - The base pairs are conserved, and new sugar-phosphate backbones are built up on them. - Both strands contain some nucleotides from the original molecule. - Both strands are made up of newly assembled nucleotides. - The sugar-phosphate chains are conserved, and new bases are inserted between them.

One strand is new, and the other is from the original molecule.

What is the first enzyme to synthesize a nucleic acid at a replication fork? - DNA polymerase - RNA Primase - helicase - topoisomerase II

RNA Primase

What would happen if telomerase stopped working in a cell in which it normally functions at high levels? - The cells would be able to divide indefinitely. - The cell would eventually die as the DNA continued to shorten. - None of the answer options is correct. - Cancer would be the result. - The cell would die immediately.

The cell would eventually die as the DNA continued to shorten.

Why are telomeres a necessary component of linear chromosomes? - They direct where DNA synthesis will end. - They direct where DNA synthesis will begin. - They fix mistakes that are made during DNA replication. - None of the answer options is correct. - They maintain the length of a chromosome because DNA is shortened every time it is replicated.

They maintain the length of a chromosome because DNA is shortened every time it is replicated.

A Southern blot is a technique that relies on hybridization of: - a nucleic acid probe to a complementary RNA. - proteins to DNA. - None of the answer options is correct. - a nucleic acid probe to a complementary DNA.

a nucleic acid probe to a complementary DNA.

Synthesis of nucleic acids always occurs in the 5′ → 3′ direction. - a nucleic acid probe to a complementary RNA. - proteins to DNA. - None of the answer options is correct. - a nucleic acid probe to a complementary DNA.

a nucleic acid probe to a complementary DNA.

Which of the following is a transgenic organism? - a human treated with insulin produced by bacteria - a bacterium that has received genes by conjugation - a fern grown in cell culture from a single fern root cell - a human given a blood-clotting factor produced in bacterial cells - a rat with rabbit hemoglobin genes

a rat with rabbit hemoglobin genes

Which of the following sequences is not a palindrome? - ATTATT - GGCGCGCC - ATTTAAAT - GGATCC - TTAATTAA

ATTATT

A graduate student wants to create a recombinant DNA molecule and introduce this molecule into bacteria. What is the proper order of steps that he should follow? - choose plasmid/donor DNA → cut with restriction enzymes → join fragments via DNA ligase →transform bacteria - transform bacteria → choose plasmid/donor DNA → join fragments with DNA ligase - choose plasmid → cut with restriction enzymes → join fragments with DNA ligase → introduce donor DNA → transform bacteria - join plasmid and donor DNA using DNA ligase → cut with restriction enzymes → transform bacteria - cut plasmid/donor DNA with restriction enzymes → transform bacteria → isolate donor DNA/plasmid → join fragments with DNA ligase

choose plasmid/donor DNA → cut with restriction enzymes → join fragments via DNA ligase

A graduate student wants to create a recombinant DNA molecule and introduce this molecule into bacteria. What is the proper order of steps that he should follow? - choose plasmid/donor DNA → cut with restriction enzymes → join fragments via DNA ligase → transform bacteria - transform bacteria → choose plasmid/donor DNA → join fragments with DNA ligase - choose plasmid → cut with restriction enzymes → join fragments with DNA ligase → introduce donor DNA → transform bacteria - join plasmid and donor DNA using DNA ligase → cut with restriction enzymes → transform bacteria - cut plasmid/donor DNA with restriction enzymes → transform bacteria → isolate donor DNA/plasmid → join fragments with DNA ligase

choose plasmid/donor DNA → cut with restriction enzymes → join fragments via DNA ligase → transform bacteria

DNA polymerase is the enzyme that separates the two strands of DNA during DNA replication. -true -false

false

During DNA replication, the leading strand contains Okazaki fragments. - true - false

false

In gel electrophoresis, DNA fragments migrate toward the negative pole of the electric field. - true - false

false

Massive parallel sequencing techniques can reliably determine the sequence of hundreds of base pairs but require more time than Sanger sequencing. - true - false

false

Okazaki fragments are ligated to form a continuous DNA molecule after replication is completed. - true - false

false

Telomerase activity in stem cells is very low. - true - false

false

The first step of PCR, called annealing, is performed by DNA polymerase. - true - false

false

The semiconservative model of DNA replication means that each DNA strand of the double helix consists of some newly synthesized DNA and some parental DNA. - true -false

false

Which of the following is an example of a transgenic organism? - fish that "glow in the dark" by expressing fluorescent jellyfish proteins - a patient who has received a kidney transplant from a close relative - a bacteria population in which a mutation conferring antibiotic resistance spontaneously arose - a human infected with the virus Hepatitis-C who expresses viral proteins - a patient who has received a heart valve from a pig

fish that "glow in the dark" by expressing fluorescent jellyfish proteins

What enzyme moves outward from the origin of replication and breaks hydrogen bonds between DNA nucleotides. - helicase - RNA primase - topoisomerase II - DNA polymerase

helicase

What is the name of the enzyme that separates the two strands of DNA during replication? - primase - DNA ligase - DNA polymerase - topoisomerase - helicase

helicase

The following enzymes play important roles in DNA replication: DNA polymerase, primase, ligase, helicase. In what order do they work during replication? - helicase, primase, DNA polymerase, ligase - primase, helicase, ligase, DNA polymerase - DNA polymerase, helicase, primase, ligase - DNA polymerase, primase, ligase, helicase - ligase, helicase, DNA polymerase, primase

helicase, primase, DNA polymerase, ligase

A DNA molecule is cut with two different restriction enzymes known to cleave it only once each. After gel electrophoresis, three different DNA fragments are detected. This result means that the original DNA molecule was: - circular. - It is not possible to make this determination from the information provided. - linear.

linear.

A eukaryotic chromosome has _____ origin(s) of replication, and a bacterial chromosome has ______ origin(s) of replication. - one, many - one, one - many, many - many, one

many, one

The point at which DNA synthesis is initiated is called the: - primase. - replication fork. - origin of replication. - start codon. - primer.

origin of replication.

The extrachromosomal DNA often found in bacteria is called a: - plasmid. - vector. - restriction enzyme. - telomere.

plasmid.

The type of genetic engineering that often involves isolating genes from one species and introducing them into another is called _____ technology. - recombinant DNA - palindromic - Sanger sequencing - DNA hybridization - Sanger recombination

recombinant DNA

What is the name of the class of enzymes that recognizes and cuts a specific sequence of DNA? - restriction enzymes - topoisomerases - DNA polymerases - helicases - primases

restriction enzymes

Which of the following is not needed for DNA replication? - DNA - nucleotides None of the answer options is correct. - enzymes - ribosomes

ribosomes

In gel electrophoresis, DNA fragments are separated based on their: - how many thymine bases are in the fragment. - charge. - size. - sequence. - how many adenine bases are in the fragment.

size.

Energy is required in order to add a nucleotide to the growing strand of DNA during replication. From where does that energy come? - DNA polymerase - primase - helicase - DNA ligase - the incoming nucleotide

the incoming nucleotide

Okazaki fragments are found on _____ strand of DNA. - the lagging - the leading - the parental - both the leading and lagging

the lagging

The name of the technique used to amplify specific sequences of DNA is: - Southern blot. - restriction. - the polymerase chain reaction (PCR). - electrophoresis. - hybridization.

the polymerase chain reaction (PCR).

All four dideoxynucleotides can be present in a single Sanger sequencing reaction and still be distinguished because: - they are labeled with different fluorescent dyes. - All of these choices are correct. - they are incorporated in the growing chain with different efficiency. - the fragments into which they are incorporated have different mobility in a gel.

they are labeled with different fluorescent dyes.

What is the function of the enzyme DNA polymerase? - to synthesize a strand of DNA using a polypeptide as a template - to synthesize a strand of mRNA using mRNA as a template - to synthesize a strand of DNA using DNA as a template - to synthesize a strand of mRNA using DNA as a template - to synthesize a polypeptide using DNA as a template

to synthesize a strand of DNA using DNA as a template

Which enzyme relieves the tension on the double helix during DNA replication? - an RNA primer - a single-stranded binding protein - DNA polymerase - helicase - topoisomerase

topoisomerase

Organisms that have been modified to contain DNA from other species are known as: - DNA hybrids. - Sanger recombinants. - recombinant DNA organisms. - transgenic organisms.

transgenic organisms.

A solution of DNA fragments of known sizes is sometimes placed in one of the wells during electrophoresis and used for size comparison. - true - false

true

DNA polymerase requires both a template and a free 3′ end to elongate a nucleotide chain. - true - false

true

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

true

In circular DNA, the DNA molecule is not shortened during each round of replication. -true -false

true

Restriction enzymes recognize certain DNA sequences and some of them will cut straight through, and others will leave an overhang at both ends of the cut. - true - false

true

Stem cells located in the gastrointestinal tract would possess more active telomerase compared to the amount of telomerase activity in mature neurons of the brain. - true - false

true

Synthesis of nucleic acids always occurs in the 5′ → 3′ direction. - true - false

true

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? - use the polymerase chain reaction - subject the DNA to gel electrophoresis - use a nucleic acid probe - None of the other answers is correct - subject the DNA to restriction enzymes

use the polymerase chain reaction