Exam Questions and CORRECT Answers
Hemophilia Pedigree - Father has hemophilia, mother does not. What is the outcome for their
kids? - CORRECT ANSWER - His daughters would be carriers. This is x-link recessive.
Autosomal:
Dominant: - CORRECT ANSWER - Autosomal: males and females equally affected.
Dominant: non-carrier parents
polymerase chain reaction (PCR) - CORRECT ANSWER - The process of copying DNA
in the lab. Uses Template DNA, Nucleotides (dNTPS), DNA Polymerase, and DNA primers.
3 Steps of PCR - CORRECT ANSWER - 1. Denaturation: DNA is heated to 95C to
separate it.
2. Annealing: reaction is cooled to 50C; primers stick to the DNA you want to copy and add
DNA polymerase.
3. Elongation: reaction heated to 70C and DNA polymerase, adding nucleotides building a new
DNA strand.
Base Excision Repair (BER) - CORRECT ANSWER - 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: - CORRECT ANSWER - 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? - CORRECT ANSWER - 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? - CORRECT
ANSWER - 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? - CORRECT ANSWER - DNA polymerase
Nonsense Mutation - CORRECT ANSWER - Change in 1 nucleotide produces a STOP
codon Stop= nonsense because it is no more.
Silent Mutation - CORRECT ANSWER - Change in 1 nucleotide but codes for the same
amino acid. Silent= the change doesn't change the name of the protein
Missense Mutation - CORRECT ANSWER - Change in 1 nucleotide leads to a code for a
different amino acid. Missense = mistake was made.
What happends during RNA splicing? - CORRECT ANSWER - During RNA splicing
introns are cut out, the remaining exons are joined together.
5'ATG AGT CTC TCT 3'
Find the DNA template strand. - CORRECT ANSWER - 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? - CORRECT ANSWER - 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) - CORRECT ANSWER - This will make a missense
mutation because it changes the name of the protein. (look at the chart provided.) missense =
mistake
DNA replication process - CORRECT ANSWER - DNA ->Transcription -> RNA ->
Translation -> Polypeptide
Describe how you would find what ionized Alanine looks like. - CORRECT ANSWER -
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. - CORRECT
ANSWER - 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.
Describe the process of neurodegenerative protein aggregation. - CORRECT ANSWER -
Alzheimer's is the most common neurodegenerative disease. The formation of aggregated
amyloid-beta fibers is another characterisitc of Alzheimer's. However, neurodegeneration and
memory loss can be detected before amyloid fibers accumulate in the brain.
What are the molecules that help denatured proteins with folding? - CORRECT
ANSWER - Molecular chaperones are protein helpers. They bind to the newly made
polypeptide and enable proper folding. Proper protein folding is vital b/c proteins that do not fold
properly can lead to a variety of diseases. Normally, the chaperones that help new proteins fold
can also help misfolded proteins refold into the correct structure.
Genetic mutations that substitute one amino acid for another can cause incorrect folding.