Micro bio ch.17

Order the migration rates of the DNA strands from FASTEST to SLOWEST during gel electrophoresis. Instructions

1. 200 nucleotides long 2. 5,000 nucleotides long 3. 8,500 nucleotides long

In cDNA synthesis, the primer for the reverse transcriptase reaction has the sequence _____.

5'-TTTTTT-3'

How many times will a plasmid with a high copy number origin replicate per host generation?

50 - 100 times

Which of the following temperatures would be appropriate for the annealing step of PCR?

50C

What happens in the extension step of PCR?

A thermostable DNA polymerase adds dNTPs to the 3'-OH end of the primers.

Which of the following is NOT a component of a PCR reaction mixture?

ATP

Sticky ends that have annealed to each other can be covalently joined by the activity of ____.

DNA ligase

The most commonly used bacterial host for cloning procedures is _____.

E. coli

True or false: DNA migrates toward the negative pole of an electrical field.

False

At what rate will small DNA fragments migrate compared to larger fragments in gel electrophoresis?

Faster

Which technique is used to separate proteins or DNA fragments by molecular weight?

Gel electrophoresis

Which two of the following statements describe a selectable marker?

Maintains selective pressure for the presence of the cloning vector in the host cell Provides a mechanism for discriminating between transformed and non-transformed host cells

Which three of the following are important features shared by all types of cloning vectors?

Multicloning site Selectable marker Origin of replication

Which three of the following are components of a cosmid?

Multicloning site Selectable marker cos site

Why does PCR result in the amplification of a specific sequence?

Only the DNA between the primers is amplified.

What is a plasmid multicloning site?

Provides multiple unique restriction sites for inserting DNA fragments into the cloning vector.

The most commonly used eukaryotic host for cloning procedures is ______.

S. cerevisiae

Which four of the following are components of a PCR reaction mixture?

Template DNA dNTPs Primers Taq polymerase

What happens in the denaturation step of PCR?

The hydrogen bonds holding the two strands of DNA are broken to produce single-stranded template DNA.

Which of the following is NOT a major type of cloning vector? Multiple choice question.

Yeast plastid

Bacterial colonies transformed by pUC19 that lack a DNA insert, will have a color of______ when grown in the presence of X-gal.

blue

A DNA molecule, such as a plasmid, that carries recombinant DNA into a host cell for replication is referred to as a(n) vector

cloning

Plasmids can be introduced into bacterial cells by _____.

conjugation and transformation

The number of plasmid molecules present in a cell is termed its _____.

copy number

In the first step of PCR, called ___, the double-stranded template DNA is separated into single strands by a temperature increase to 95°C.

denaturation

During PCR, the temperature is raised to 95°C in one step of each cycle to _____.

denature the DNA template

It is a common practice to insert a gene of interest into a site found in many commercially available plasmids.

multi cloning

Conjugation, transformation, and electroporation are all methods for _____.

transferring a plasmid cloning vector to a microbe

In the shuttle vector YEp24, the selectable marker in yeast is a gene that encodes a protein that is essential________for biosynthesis, and the selectable marker in bacteria is a gene that encodes a protein that confers resistance to the antibiotic_________.

uracil, ampicillin

In the presence of X-gal, bacterial colonies transformed by pUC19 that contains insert DNA will have a color of _____.

white

Place the steps of the polymerase chain reaction in the correct order.

1. Denaturation 2. Annealing 3. Extension

Which of the following temperatures would be appropriate for the denaturation step of PCR?

95 degreesC

Which of the following are steps of the polymerase chain reaction?

Annealing Extension Denaturation

Which type of cloning vector can contain the largest amount of insert DNA?

Artificial chromosomes

Which two of the following are advantages of plasmid cloning vectors?

Autonomous replication Easy to purify

Which statement about the stability of artificial chromosomes is true?

BACs are more stable that YACs

Which four of the following are major types of cloning vectors?

Bacteriophages Artificial chromosomes Cosmids Plasmids

Which of the following is NOT a characteristic of yeast artificial chromosomes?

Based on F fertility factor

Which of the following would be useful to a scientist who wanted to put DNA from one organism into a different organism and then make many copies of it?

Cloning vector

Which two of the following are characteristics of phage vectors?

Contains unique restriction sites Contains phage genes for host lysis

The ____, ____ reaction is a technique that allows the production of a large number of copies of a specific DNA sequence from a complex mixture of sequences.

DNA amplification

Sticky ends that have annealed to each other can be covalently joined by the activity of ____. Multiple choice question.

DNA ligase

Which enzyme forms phosphodiester bonds between cloned DNA fragments and the cloning vector?

DNA ligase

Which technique can amplify a specific sequence of DNA from a complex mixture of DNA sequences?

Polymerase chain reaction

The most commonly used thermostable DNA polymerase for the polymerase chain reaction is ____.

Taq polymerase

Which of the following is NOT an important feature of all types of cloning vectors?

Telomere sequence at each end

Which four of the following are characteristics of a yeast artificial chromosome?

Telomere sequences at each end Centromere sequence Multicloning site A selectable marker

True or false: Sticky ends created by the same restriction enzyme can hydrogen bond with each other.

True

The selectable markers for the shuttle vector YEp24 are ____.

URA3 ampR

When selecting bacterial cells that have taken up a recombinant DNA molecule created in pUC19, the antibiotic ampicillin is included in the medium to ensure that _____.

all colonies carry the plasmid

The selectable marker for the pUC19 plasmid is _____.

ampR

In the plasmid pUC19, the selectable marker is a gene that encodes resistance to the antibiotic

ampicillin

Making a large number of copies of a specific DNA sequence is referred to as ____.

amplification

The process to produce a large number of copies of a specific DNA sequence is referred to as DNA .

amplification, or PCR

In cDNA synthesis, the product of the reverse transcriptase reaction is _____.

an RNA-DNA hybrid

During PCR, the temperature is maintained at about 50°C in one step of each cycle to _____.

anneal the primers

In the second step of PCR, called___ , the oligonucleotide primers base pair with their complementary sequences in the single-stranded template DNA.

annealing

Bacterial or yeast________are_________ cloning vectors that are useful for cloning very large amounts of DNA such as the amount necessary to build a genomic library.

artificial chromosomes

When cloning a DNA fragment into a plasmid vector, it is critical that both the vector and the DNA fragment are digested with the same restriction endonuclease because _____. picture

both the vector and the DNA fragment must have the same sticky ends

Which of the following is a hybrid cloning vector, containing DNA sequences from both plasmids and phages? Multiple choice question.

cosmid

When screening bacterial cells that have taken up a recombinant DNA molecule created in pUC19, the chemical X-gal is included in the medium to _____.

distinguish colonies whose plasmids have an insert from those that don't have the insert

Two commonly used methods for introducing recombinant DNA into host organisms are ____ and ____.

electroporation chemical transformation

True or false: Yeast artificial chromosomes are more stable than bacterial artificial chromosomes.

false

A technique that uses an electrical field to separate DNA fragments by molecular weight through a matrix such as agarose is

gel electrophorus

The modification of the genetic code of a living organism is called _____.

genetic engineering

The use of a plasmid with a(n) number origin of replication would dramatically increase the amount of cloned product produced by the host cell.

high copy

Sticky ends that have been created by the same restriction endonuclease can associate with each other by _____.

hydrogen bonds

The origin of replication allows the plasmid to replicate _____.

independently of the host chromosome

In pUC19, which gene sequence is interrupted by the presence of insert DNA? picture

lacZ

The multicloning site in pUC19 is located in the 5' region of a gene called , which encodes the enzyme that cleaves lactose into glucose and galactose. (Leave out any Greek symbols.)

lacZ

Once the sticky ends of the cloned DNA and cloning vector have formed complementary base pairs by hydrogen bonding, the two fragments can be covalently joined by adding the enzyme DNA_____to the reaction mixture.

ligase

The enzyme DNA is used to covalently join DNA fragments that have associated through complementary base pairing between their sticky ends.

ligase

Genetic engineering includes _____. [Choose three.]

modifying bacteria to produce vitamins breeding animals for desirable traits crossing crop plants to improve yield

It is a common practice to insert a gene of interest into a __________ site found in many commercially available plasmids.

multi cloning ( polylinker, or MCS)

The region of a cloning vector that contains several unique restriction sites intended for the insertion of a DNA sequence is called the site.

multi-cloning

The_______of________ allows a plasmid to replicate independently of the host chromosome.

origin, replication

_______vectors are engineered genomes of bacterial viruses that contain unique restriction sites and the genes necessary for host lysis.

phage

Host cells transformed by plasmids containing insert DNA can be distinguished from cell transformed by plasmid with no insert by _____.

placing the multicloning site into a gene whose protein product has a detectable activity such as the production of blue vs. white colonies

are circular cloning vectors that replicate autonomously and are easy to purify.

plasmids

In an electrical field, DNA will migrate towards the pole with the charge.

positive

Oligonucleotide sequences complementary to sequences flanking the DNA sequences to be amplified in the polymerase chain reaction are called .

primers

Oligonucleotides that serve as the 3'-OH needed for DNA synthesis in the polymerase chain reaction are called _____.

primers

The____________of a PCR reaction determines the exact DNA sequence that will be amplified from the template DNA.

primers

An enzyme that recognizes and cleaves specific nucleotide sequences is called a(n) ____. Multiple choice question.

restriction endonuclease

The reaction illustrated in the image is catalyzed by a _____.

restriction endonuclease

Enzymes that cut DNA at a specific sequence of nucleotides are referred to as .

restriction enzyme

Restriction endonucleases are also called ____.

restriction enzymes

Restriction endonucleases are also referred to as .

restriction enzymes

A gene whose presence confers the ability to survive in particular conditions is called a(n) ______.

selectable marker

Plasmids and other vectors that contain two origins of replication recognized by different host organisms are called vectors.

shuttle

A plasmid that contains two origins of replication recognized by different host organisms is called a _____.

shuttle vector

Some restriction enzymes cleave DNA in a manner that results in the production of unpaired nucleotides called ____.

sticky ends

The circled 4-nucleotide single-stranded regions of DNA present at the ends of the reaction products are termed _____. Multiple choice question.

sticky ends

When the restriction endonuclease EcoRI cleaves a DNA molecule, it produces unpaired nucleotide sequences called at the cut ends.

sticky ends

During PCR, the temperature is maintained at about 68-72°C in one step of each cycle to _____.

synthesize a new DNA strand

When cloning a DNA fragment into a plasmid vector, it is critical that the restriction endonuclease used cuts the plasmid only once because _____.

the entire plasmid is needed to propagate the inserted DNA fragment

When cloning a DNA fragment into a plasmid vector, it is critical that the restriction endonuclease used cuts the plasmid only once because _____. Multiple choice question. picture with cloning

the entire plasmid is needed to propagate the inserted DNA fragment

Plasmid copy number refers to _____.

the number of plasmid molecules present in a cell

Chemical ____ and____ (a technique that uses high-voltage electricity), are two commonly employed methods for the introduction of recombinant DNA into host organisms.

transformation and electroporation