Genetics - Chapter 13

Two of the most widely used cloning methods are embryo splitting and nucleotide fusion.

False

When DNA is cut with restriction enzymes, fragments of the same size are produced.

False

When an adult animal is cloned, the resulting cloned offspring is genetically different from the original adult animal.

False

What is an advantage of PCR over DNA cloning?

PCR can amplify DNA present in scarce quantities.

What is the purpose of a vector in DNA cloning?

The vector carries foreign DNA molecules into bacterial host cells for replication.

Why were yeast artificial chromosomes (YACs) the vector of choice for the Human Genome Project?

YACs can carry much more DNA per vector than plasmids.

During the Southern blot technique, the cut DNA in the gel is ________ to single strands to enable a labeled probe to bind to complementary sequences of interest in the fragments.

denatured

During in vitro fertilization, the fertilized egg ____.

develops in a Petri dish to form an embryo containing four to eight cells

The amount of DNA ______ with each PCR cycle.

doubles

DNA synthesis

following the binding of primers to the template strand, DNA polymerase makes another DNA strand by adding complementary base pairs to the sequence

In order to identify a specific gene in a genomic library, the library is screened with a ________ complementary to the ________.

labeled probe; desired gene

​In June 2001 an announcement was made that a draft sequence of the ____________________ nucleotides in the human genome had been finished.

3.2 billion

The ability to isolate and produce many copies of specific _______ molecules had a great impact on many areas of genetic research.

DNA

After a restriction enzyme cuts DNA into fragments and the fragments pair with complementary bases, the enzyme _______ is used to seal the gaps in the phosphate backbone.

DNA ligase

In recombinant DNA techniques, the gaps in the paired DNA fragments are closed by ____.

DNA ligase

Detecting single nucleotide polymorphisms (SNPs), fusion genes, and mRNAs for alternative splicing are three applications of _______

DNA microarrays

To discover which genes are expressed in normal vs. cancerous cells, the mRNA from both cell types can be compared by ________.

DNA microarrays

What is the advantage of using DNA microarrays for analyzing gene expression?

DNA microarrays can analyze the expression of thousands of genes in a single experiment.

The polymerase chain reaction (PCR) consists of multiple cycles of ________, resulting in ________ copies of a desired DNA sequence.

DNA replication; millions or billions of

Vectors can transfer ____.

DNA sequences into bacterial host cells for cloning

Using ________, DNA from an extinct giant sloth can be compared to DNA from living sloths to reveal ________.

DNA sequencing; evolutionary relationships

Adult cells cannot be used as the source of nuclei for cloning animals.

False

Artificial selection is the process by which new species arise due to the accumulation of genetic mutations that allows adaptation to a changing environment.

False

Artificial selection results from the cloning of all of the DNA sequences present in one individual.

False

Cloned dairy cows are unable to produce milk.

False

DNA cloning is the best way to obtain DNA sequences from scarce quantities of extinct animal tissue.

False

DNA cloning is the only way to obtain large quantities of specific DNA sequences for study.

False

DNA ligase adds the stickiness to the ends of the DNA fragments from different sources.

False

DNA microarrays are useful for analyzing five to ten genes in a single experiment.

False

DNA sequencing is the process of amplifying the amount of DNA in a test tube.

False

In PCR, the DNA used must be purified, though it can be present in very small quantities.

False

Plasmids are short sequences of DNA used as primers in PCR.

False

________ allows scientists to identify, map, isolate, and sequence genes.

Recombinant DNA technology

In step 5 in the figure above, _______ creates a complementary DNA strand beginning at the primers.

Taq polymerase

A collection of clones containing all the DNA sequences carried by an individual is called a genomic library.

True

Because it is so large, new technology was needed to clone all of the DNA sequences in the human genome.

True

Clones are derived from a single ancestor.

True

Cloning can also be done by directly injecting nuclei from adult cells into enucleated eggs. This method has a much higher success rate than cell fusion.

True

DNA from many sources can be used for PCR.

True

During gel electrophoresis, DNA fragments are separated by size.

True

One use of a genomic library is to locate and identify specific − desired − DNA sequences.

True

PCR can be used to replicate a single DNA molecule.

True

Recombinant DNA technology revolutionized molecular biology research.

True

Repeating the sequence of the polymerase chain reaction doubles the number of DNA fragments each time.

True

The DNA to be cloned is cut with a restriction enzyme and this same restriction enzyme is used to cut the plasmid vector into fragments.

True

To analyze which genes are expressed − or switched on − in a given cell, mRNA must be studied.

True

To obtain many copies of a cloned DNA molecule, it is necessary to introduce the cloned DNA into a host cell for replication.

True

Two DNA molecules will link together if they have complementary base sequences.

True

When DNA fragments from two different sources are mixed together they base pair with each other at their sticky ends.

True

​Most often, genomic library screening uses ____.

a labeled, complementary single-stranded RNA or DNA molecule called a probe

A DNA microarray is ____.

a series of short nucleotide sequences placed on a solid support and has several uses

To clone an animal by embryo splitting, ____.

an unfertilized egg is collected from a donor mother and then fertilized in a dish by in vitro fertilization

Plant and animal food sources have been improved by _______ for thousands of years.

artificial selection

recognition site

at this specific base sequence, the enzyme cuts through both strands of DNA

A restriction enzyme is a ____.

bacterial enzyme that cuts DNA at specific sites​

A(n) ________ is a collection of the cloned genes from a single chromosome.

chromosomal library

DNA restriction enzymes ________ DNA molecules, while DNA ligase ________ two DNA molecules.

cut; pastes together

DNA cloning techniques have made it possible to locate ______, map them, isolate them, sequence them, and transfer them between species.

genes

The process of embryo splitting results in offspring that are ________.

genetically identical to each other

A collection of clones that contain all of the genetic information carried by a genome is called a:

genomic library

An advantage of YACs over other vectors in cloning human genes is that they ____.

have a higher capacity for carrying long DNA fragments

During the process of artificial selection, ________.

humans select which individuals to mate

​During the denaturation step of PCR, ____ bonds are broken when DNA is heated.

hydrogen

Southern blots are useful for ________.

isolating and identifying DNA fragments that have been separated by gel electrophoresis

A 2005 study concluded that ________ differences exist in products from cloned and noncloned food animals.

no significant

A technique called the ______ has revolutionized molecular biology because it is not as labor intensive or time consuming as DNA cloning techniques.

polymerase chain reaction

During PCR, ______ serve as a starting point for the synthesis of the new DNA strand.

primers

hybridization

primers bind to the DNA template strand

A series of techniques in which DNA fragments from an organism are linked to self-replicating vectors to create recombinant DNA molecules, which are then replicated in a host cell, is called ________

recombinant DNA technology

vector

self-replicating carrier DNA molecules used to transfer DNA segments into host cells

PCR uses two components: ____________________ that serve as templates and primers that bind to regions on either side of the template to be copied.

single strands of DNA

plasmid

small circular DNA molecules carried by bacteria

Step 4 in the figure above shows primers bound to single DNA strands. These primers are the _______ for the synthesis of the new DNA strand.

starting point

recombinant DNA technology

techniques used to create DNA molecules - DNA fragments from an organism are linked to self-replicating vectors

restriction enzyme

these move along the DNA molecule until they reach a specific base sequence where they cut both strands of DNA

denaturation

this causes the two DNA strands to unwind and separate

Southern blot is a method for ____.

transferring DNA fragments from a gel to a membrane filter and used in hybridization experiments

In PCR, cooling the mixture of DNA and primers _______

unwinds the double-stranded DNA fragments

In PCR, heating the mixture of DNA and primers ______

unwinds the double-stranded DNA fragments

These vectors can carry DNA fragments up to 1,000,000 bases long:

yeast artificial chromosomes (YACs)

A yeast artificial chromosome (YAC) is a ____ that can accommodate large DNA inserts and uses the eukaryote yeast as a host cell.

​cloning vector that has telomeres and a centromere

During the process of gel electrophoresis, the DNA fragments migrate due to the effects of ____.

​electrical charge

The discovery that some bacteria ____ using enzymes that cut the viral DNA into pieces was one of the first steps in the development of recombinant DNA technology.

​resist viral infection

Nuclear transfer is a preferred method of cloning over embryo splitting because it ____.​

​results in a larger number of cloned offspring