Exam 2

Question 1

What is the order of the transcription steps?

Answer 1

1. RNA polymerase II binds to the promotor
2. DNA helix is unwound and RNA is synthesized
3. Transcription is stopped by a hairpin loop

Question 2

What two roles are played by the RNA polymerarse II during transcription?

Answer 2

1. Binds to protein

2. unwinds the DNA helix and synthesizes RNA

Question 3

The formation of what ends transcription?

Answer 3

Hair pin loop

Question 4

List the three steps involved in processing RNA.

Answer 4

1) Add 5 prime Guansine triphosphate cap
2) Add a 3 prime Poly A tail
3) Splice out introns and rebond exons

Question 5

What is the function of the spliceosome?

Answer 5

Removes introns

Question 6

What is the order of the schematic nucleotides?

Answer 6

GU, A, AG

Question 7

What is alternative splicing?

Answer 7

Allows the intron to become an exon

Question 8

What is the difference between exons and introns?

Answer 8

Both are Transcribed
Exons are translated
Introns are never translated

Question 9

What happens in the Aminoacyl site in translation?

Answer 9

Link an amino acid on a tRNA to a codon

Question 10

What are the functions of the three types of RNA required for translation to take place?

Answer 10

mRNA- codes for protein
tRNA-serves as a link between AA and codon
Ribosomal-Peptide bond between amino acid

Question 11

What is the start codon?

Answer 11

AUG

Question 12

What are the Stop Codons?

Answer 12

UAG, UGA, UAA

Question 13

Transcription factors bind two DNA sequence and one protein to increase expression of a gene. What are the DNA sequences and proteins?

Answer 13

Enhancer, Promotor and Polymerase II

Question 14

The enhancer may be located tens of thousands of nucleotides away from the promotor. How does the transcription factor bind to the enhancer and promotor simultaneously to increase gene expression.

Answer 14

The DNA is flexible and can loop back to the enhancer

Question 15

List the order of microRNA processing in the correct order.

Answer 15

1) Immature microRNA is transcribed from DNA
2) Drosha removes the hair pin loop
3) Dicer removes the loop in the hair pin loop
4) RISC removes the miRNA-star

Question 16

What role does Drosha play in processing?

Answer 16

Cuts off the hairpin loop from the sequence

Question 17

What role does Dicer play in microRNA processing?

Answer 17

Binds and degrades the hair pin loop

Question 18

What role does the RNA-induced silencing complex play in microRNA processing?

Answer 18

Removes the miRNA

Question 19

Compare and contrast repressor proteins and transcription factors in regulating gene expression

Answer 19

Both change gene expression
Repressors down regulate-sits on the promotor and blocks transcription, only binds to promotor
Transcription factors- up regulate-bind to enhancer and promotor

Question 20

How does microRNA decrease gene expression when the microRNA is:

1) Completely complementary to mRNA
2) Partially complementary

Answer 20

1) RISC cleaves the mRNA

2) RISC can’t cleave but can sit on the sequence and prevents ribosome from translating

Question 21

Define epigenetic.

Answer 21

Affects the expression of a gene but doesn’t change the actual genetic sequence.

Question 22

What happens to a gene when it becomes highly methylated?

Answer 22

Can begin silencing the gene by tightly wrapping around itself and down regulates expression

Question 23

What happens to a gene when it becomes un-methylated?

Answer 23

Gene relaxes and uncoils and allows gene expression to increase

Question 24

An increase in what can cause increased gene expression?

Answer 24

histone acetylation

Question 25

What about genetics can change with time?

Answer 25

Epigenome

Question 26

What causes changes to an individual epigenome?

Answer 26

Environment, Diet and Stress

Question 27

What is transgenerational epigenetic inheritance?

Answer 27

Changes in DNA methylation that can be transmitted across generations

Question 28

What is the purpose of gel electrophoresis?

Answer 28

To ensure PCR worked, assists in determining size of DNA strands

Question 29

What is the purpose of PCR?

Answer 29

PCR allows us to zoom in and observe the gene sequence. It amplifies the DNA by increasing magnitude

Question 30

Name three reagents that are needed for completion of the polymerase chain reaction and the purpose of each reagent?

Answer 30

DNA-must be added for it to be amplified Primers-DNA sequence that binds to the gene to amplify Nucleotides-Must be able to make many copies

Question 31

What happens at the different temperatures of a PCR cycle?

Answer 31

95 degrees-Denature, unwinds the helix-allows primers to enter 50-60 degrees- temp allows primers to bond 72 degrees- Replication

Question 32

What size DNA fragments are expected to move through the gel faster?

Answer 32

Small

Question 33

How does the polymerase chain reaction amplify DNA?

Answer 33

Exponentially

Question 34

Are DNA fragments negative or positively charged?

Answer 34

Negative

Question 35

What is the difference between Taq DNA polymerase and DNA Polymerase III?

Answer 35

Taq is thermal protected and can with stand the 95 degree C heat DNA polmerase III would denature at 95 degrees C

Question 36

How is the size of a DNA fragment determined on a gel?

Answer 36

The gel has a DNA ladder system, Known DNA is placed in one well and all other DNA is measured against it

Question 37

What is a SNP Chip?

Answer 37

Test that can genotype thousands of SNPs at one time

Question 38

How can a SNP chip be used in the livestock industry?

Answer 38

Can predict the genetic merits of an animals traits | Can also be research

Question 39

Why is the efficiency of cloning low?

Answer 39

Because methylation marks werent reprogrammed correctly is the most common issue seen

Question 40

What is imprinting?

Answer 40

A gene from one parent (mother or father) is epigenetically silenced when transferred to the offspring

Question 41

List one advantage and one disadvantage of cloning in livestock

Answer 41

Disadvantage-Lacks genetic pool | Advantage-Maintain valuable genetic merit

Question 42

Why would a producer choose to use sex semen?

Answer 42

If they wanted to produce more bull or heifer calves

Question 43

Why is sex semen used more in the dairy industry than the beef industry?

Answer 43

In dairy the females make the money so youd want more heifers. Dairy also uses more AI than beef.

Question 44

Explain how the Cas9-CRISPR targets a gene for modification.

Answer 44

The guide RNA leads the Cas9 to the target and the CAS9 unwinds and cuts the helix. The sequence then attempts to match with replacement

Question 45

What needs to be added to the Cas9-CRISPER system to modify with the right sequence that has genetic change?

Answer 45

Must be provided with the right sequence that has the genetic change

Question 46

The Cas9-CRISPR system exists in bacterial cells. What is its function in bacterial cells?

Answer 46

Protect the bacteria from viruses

Question 47

What is the change inAquaBounty Advantage salmon?

Answer 47

They grow twice as fast and help reduce the costs of production

Question 48

What does PCR stand for?

Answer 48

Polymerase Chain Reaction

Question 49

What is the difference between a cloned animal and a gene edited animal?

Answer 49

Cloned will have the exact same genome and creates the same animal Gene edited animals will change the actual genetic code

Question 50

Explain how Cas9-CRISPR has the potential to revolutionize the field of gene editing in livestock.

Answer 50

Can make multiple genetic changes at one time

Question 51

List two examples of how gene editing could benefit livetstock.

Answer 51

1) Feed efficiency 2) Carcaus Quality 3) Environment Impact

Question 52

List two concerns of opponents of gene editing in livestock

Answer 52

1) Cost 2) Unintended consequences 3) Public Preception

Question 53

Describe Enviro Pig

Answer 53

They had a phytase gene changed in their salivary glands to degrade phosphate to decrease the environmental impact

Question 54

Describe the steps involved in cloning an animal by somatic cell nuclear transfer.

Answer 54

1) Isolate donor cells from the animal to be cloned and the egg donor 2) Remove and discard the nucleus from the egg cell 3) Transfer somatic cell nucleus to the egg cell-rest 4) Stimulate cell division 5) Implant embryo in surrogate mother 6) Deliver the baby