Chapter 10 Genetic Engineering

Question 1

What best describes a transgenic animal?

Answer 1

An animal whose chromosomes contain DNA from an external source

Question 2

About 80% of the genes present in humans are also present in the mouse genome.

Answer 2

True

Question 3

What term represents the hereditary information that it present in an animal?

Answer 3

Genome

Question 4

What is a transgene?

Answer 4

The fragment of DNA that is introduced into the nucleus of a cell.

Question 5

Barrier access to an animal room increases the risk of introducing disease entities to valuable genetically modified lines.

Answer 5

False

Question 6

Whenever a dam experiences dystocia, oxytocin is effective at inducing labor.

Answer 6

False

Question 7

A gene’s phenotype develops in utero and can always be observed after birth..

Answer 7

False: it can develop in utero and also during develop or adulthood

Question 8

Overbreeding to obtain the number of mice needed with a particular genotype is unacceptable in a transgenic animal facility

Answer 8

False

Question 9

If a large number of animals must be euthanized because of gene expression is inadequate, animal care staff may need emotional support.

Answer 9

True

Question 10

Genetically modified mice have the same housing and nutrition needs as any other mice in the facility.

Answer 10

False

Question 11

Every transgenic animal facility should have a mechanism for observing, documenting, and reporting health concerns regarding breeding or unique phenotypes.

Answer 11

True

Question 12

With barrier access to a room, investigators must rely on animal care staff to handle all animal needs.

Answer 12

True

Question 13

What might affect transgenic mice and the success of their breeding?

Answer 13

Noise, odors, and lighting

Question 14

Females with a litter from implanted fertilized eggs are called:

Answer 14

Surrogate mothers

Question 15

What is an initial observation indicating successful mating?

Answer 15

Vaginal plug

Question 16

In the production of gene-targeted animals, mating with a stud makes the recipient female pseudopregnant.

Answer 16

False

Question 17

Placing pups with a female other than the one who gave birth to them is called cross-fostering.

Answer 17

True

Question 18

If fertilized eggs are required, along with egg donor females, what animals are required?

Answer 18

Stud males

Question 19

Embryos can be transferred to recipient mice surgically if the embryos are at least 3.5 days old.

Answer 19

False: Embryos can be transferred to recipient mice surgically only if the embryos are less than 3.5 days old.

Question 20

Pronuclear injection provides the scientist with a more specific tool than gene-targeted mutation for placement of the transgene.

Answer 20

False

Question 21

To construct a transgene, the scientist must start with an existing piece of DNA that originated in a living organism.

Answer 21

False

Question 22

A transposon is a DNA sequence obtained from bacteria.

Answer 22

True

Question 23

Pronuclear injection introduces a transposon-flanked DNA sequence with an enzyme that inserts multiple copies of the DNA into the genome.

Answer 23

False: a single copy

Question 24

PCR can be used to genotype an animal born after pronuclear injection of a transgene.

Answer 24

True

Question 25

If a transgene is intergrated in one of the chromosomes of a pair, the animal is said to be:

Answer 25

hemizygous

Question 26

What best describes "alleles"?

Answer 26

Copies of the same gene

Question 27

Wild-type animals are more commonly used to start a transgenic line because it is easier to observe a phenotype change than in inbred strains.

Answer 27

False: inbred strains are used because a phenotypic change is easier to see.

Question 28

All animals produced by pronuclear injections of the same transgene have the same phenotype.

Answer 28

False

Question 29

Offspring of two hemizygous parents inherit at least a copy of the transgene.

Answer 29

False: in theory, 25% of the offspring will have NO copy of the transgene.

Question 30

Eukaryotic cells have the ability to develop into any kind of cell in the body.

Answer 30

False: embryonic stem cells.

Question 31

CRISPR is an engineered DNA identification mechanism.

Answer 31

False: CRISPR is a naturally occurring DNA identification mechanism

Question 32

The gene-targeted mutation derived from the injected embryonic stem cells is always present in the sperm of a male chimera.

Answer 32

False

Question 33

To test for germline transmission, chimeras are mated to animals of the same strain from which their ES cells were derived.

Answer 33

False: Chimeras are mated to animals of the same strain as the blastocyst host.

Question 34

Using engineered systems for gene targeting eliminates the need for embryonic stem cell culture

Answer 34

True

Question 35

Mouse models have been developed hat replace the mouse immune system with a human system.

Answer 35

True

Question 36

What is a genetically engineered animal that has had one or more genes from its genome functionally removed?

Answer 36

Knockout

Question 37

Embryonic stem cells used for gene-targeted mutations are grown in the presence of antibiotics.

Answer 37

True

Question 38

CRISPR/Cas9 may be used to selectively knock out genes of interest.

Answer 38

True

Question 39

In genetically engineered mice known as knockouts, the transngene of interest is functional.

Answer 39

False

Question 40

Tail biopsies on adult mice should be done under anesthesia.

Answer 40

True

Question 41

What test might be used to assess the phenotype of mutant animals?

Answer 41

Imaging techniques Neurological test Behavioral test

Question 42

In order to avoid disturbing the litter, the best time to genotype a mouse is within two days of birth.

Answer 42

False: the best time is around weaning time

Question 43

The phenotype of mutant animals indicates the engineered change in the DNA

Answer 43

True

Question 44

Backcrossing founders to wild-type animals can be used to:

Answer 44

- Ensure germ lines transmission of an induced mutation - Cross a hybrid with one of its parents - move a gene generated in one inbred strain to another.

Question 45

Cryopreservation can be used to store frozen embryos, and subsequently recover the original genetic make-up of a mouse line when genetic drift has caused changes in the strain.

Answer 45

True

Question 46

The Mutant Mouse Regional Resource Centers serve as a centralized repositories for many mouse lines.

Answer 46

True

Question 47

What techniques allows a mouse strain to be taken "off the shelf" but still be available for use when needed?

Answer 47

Crypreservation

Question 48

Sperm cryopreservation is a terminal procedure.

Answer 48

True

Question 49

What is the goal of genotyping?

Answer 49

To determine if a specific DNA fragment is present in the genome of an organism.

Question 50

Best describes genetic engineering?

Answer 50

Manipulating DNA molecules to alter their composition.

Question 51

Using the pronuclear injection technique, what is the average percentage of offspring carrying the transgene?

Answer 51

20%

Question 52

What is the best way to describe genetic engineering?

Answer 52

Manipulating DNA molecules to alter their composition

Question 53

What is a transgene?

Answer 53

The fragment of DNA that is introduced into the nucleus of a cell

Question 54

Using the pronuclear injection technique, what is the average percentage of offspring carrying the transgene?

Answer 54

20%

Question 55

If a transgene is integrated in one of the chromosomes of a pair, the animal is said to be:

Answer 55

hemizygous

Question 56

What best describes a congenic strain?

Answer 56

The result of backcrossing for 10 generations