WGU 785 Final Exam
Hemophilia Pedigree – Father has hemophilia, mother does not. What is the
outcome for their kids?
(ANS- His daughters would be carriers. This is x-link recessive.
Autosomal:
Dominant:
(ANS- Autosomal: males and females equally affected.
Dominant: non-carrier parents
polymerase chain reaction (PCR)
(ANSThe process of copying DNA in the lab. Uses Template DNA, Nucleotides
(dNTPS), DNA Polymerase, and DNA primers.
3 Steps of PCR
(ANS1. Denaturation: DNA is heated to 95C to separate it.
- Annealing: reaction is cooled to 50C; primers stick to the DNA you want to
copy and add DNA polymerase. - Elongation: reaction heated to 70C and DNA polymerase, adding nucleotides
building a new DNA strand.
Base Excision Repair (BER)
(ANS- How you repair a mutation. BER is used to repair damage to a base caused
by harmful molecules. You remove the base that is damaged and replace it. BER removes a single nucleotide
DNA glycolsylase – sees damaged DNA and removes it.
DNA polymerase-puts the right one back in while DNA ligase seals it.
Mismatch repair (MMR) occurs during:
(ANS- replication. DNA polymerase proofreads but sometimes a mismatch pair
gets through. MMR removes a large section of the nucleotides from the new DNA
and DNA polymerase tries again. (Ex: C-T instead of C-A)
Mismatch Repair corrects what kind of DNA damage?
(ANS- When a base is mismatched due to errors in replication. Such as G-T
instead of G-C. DNA polymerase comes by and fixes it.
What happens when DNA polymerase binds to DNA to make RNA?
(ANS- TRANSCRIPTION! DNA polymerase takes the individual nucleotides and
matches them to the parental sequences to ensure a correct pair. It must bind with
RNA primer to work.
What is needed for DNA replication?
(ANS- DNA polymerase
Nonsense Mutation
(ANS- Change in 1 nucleotide produces a STOP codon Stop= nonsense because it
is no more.
Silent Mutation
(ANS- Change in 1 nucleotide but codes for the same amino acid. Silent= the
change doesn’t change the name of the protein
Missense Mutation
(ANS- Change in 1 nucleotide leads to a code for a different amino acid. Missense
= mistake was made.
What happends during RNA splicing?
(ANS- During RNA splicing introns are cut out, the remaining exons are joined
together.
5’ATG AGT CTC TCT 3′
Find the DNA template strand.
(ANS- 3’TAC TCA GAG AGA 5′
The DNA template strand is complimentary. So start with the opposite number,
then go L-R with the complimentary letter.
5’ATG AGT CTC TCT 3′
What is the corresonding mRNA sequence?
(ANS- 5’AUG AGU CUC UCU 3′
This sequence is the same as the coding strand except T changes to U because it is
RNA. RNA doesn’t have T.
How would a mutation from CTC to ATC affect the protein sequence? (CTC/ATC
- coding strand, AUC – mRNA strand)
(ANS- This will make a missense mutation because it changes the name of the
protein. (look at the chart provided.) missense = mistake
DNA replication process
(ANS- DNA ->Transcription -> RNA -> Translation -> Polypeptide
Describe how you would find what ionized Alanine looks like.
(ANS- This is an amino acid. Look for the “R” group. Alanine is a hydrophobic
amino acid that has CH3. It is a weak interaction. An ionized acid will have a + or - charge.
Describe what causes the misfolding of protein in Alzheimer’s Disease.
(ANS- Protein misfolding is caused by intracellular tangles and extracellular
plaques (senile plaques) caused by abnormal protein aggregation.
TAU is fibrous material inside cells where the connections are lost. This becomes
defective and forms filaments in the neuron.
Amyloid-Beta is a large precursor protein in the cell. Excess amyloid-beta creates
senile plaques. This starts in the hippocampus and moves up.