WGU BIOCHEMISTRY 785 TRAINING STUDY
SHEET 2026 UPDATED QUESTIONS AND
ANSWERS
◉what is the relationship between mRNA and tRNA? Answer: tRNA
is complementary to mRNA
◉how does mRNA splicing allow use to create multiple proteins
from a single gene/mRNA? Answer: Alternative splicing allows for
all introns to be cut and some exons = multiple proteins form from
same MRNA
◉what factors increase gene expression? Answer: Decreased
methylation, increased acetylation, Widely spaced neucleosomes,
exposed promoter, use of transcription factors, use RNA polymerase
◉what factors decrease gene expression? Answer: Increased
methylation/decreased acetylation, tightly packed nucleosomes,
hidden promoter, no transcription factors, no RNA polymerase
◉what steps do you take to determine what type of mutation
occurred between a normal and mutated DNA/RNA sequence?
,Answer: look between the two strands, determine what changed,
name the mutation
◉What are the types of mutations? Answer: silent, missense,
nonsense, frameshift
◉what type of DNA damage does each repair pathway fix? Answer:
base excision - single nucleotide, nucleotide excision repair -
multiple nucleotides, missmatch - mistakes made in DNA replication,
homologous recombination/nonhomologous end joining - double
stranded breaks
◉what are the steps of excision repair? Answer: Recognize damage,
cut damage out, recreate DNA strand, glue DNA strand back together
◉what are the steps of mismatch repair? Answer: Remove
mismatched base, try again
◉what are the steps of homologous recombination and
nonhomologous end joining? Answer: HR uses DNA from unbroken
strand to fix broken strand, NHEJ reconnects broken pieces, may
have pieces missing
◉what are the steps of PCR? Answer: denature, anneal,
elongation/extension
, ◉how do we denature DNA in PCR? Answer: heat to 95 degrees C to
separate DNA strands
◉how do we anneal DNA? Answer: primers base pair with DNA
strands
◉how do we elongation/extend DNA? Answer: DNA polymerase
attach primers and synthesize new DNA strands
◉what are the components of PCR? Answer: target DNA, heat stable
DNA polymerase, nucelotides (dNTP), primers
◉how are primers used to assist in a PCR reaction? Answer:
Primers allow DNA polymerase to bind to target DNA
◉how do you calculate the number of copies of DNA produced by
specific number of PCR cycles? Answer: Each cycle produces
doubles the amount of DNA
◉how does PCR compare to normal DNA replication in the cell?
Answer: RNA primers used instead of DNA in normal replication.
Helicase enzymes separate DNA strands instead of heat in normal
replication. DNA polymerase is not heat stable in normal replication.
SHEET 2026 UPDATED QUESTIONS AND
ANSWERS
◉what is the relationship between mRNA and tRNA? Answer: tRNA
is complementary to mRNA
◉how does mRNA splicing allow use to create multiple proteins
from a single gene/mRNA? Answer: Alternative splicing allows for
all introns to be cut and some exons = multiple proteins form from
same MRNA
◉what factors increase gene expression? Answer: Decreased
methylation, increased acetylation, Widely spaced neucleosomes,
exposed promoter, use of transcription factors, use RNA polymerase
◉what factors decrease gene expression? Answer: Increased
methylation/decreased acetylation, tightly packed nucleosomes,
hidden promoter, no transcription factors, no RNA polymerase
◉what steps do you take to determine what type of mutation
occurred between a normal and mutated DNA/RNA sequence?
,Answer: look between the two strands, determine what changed,
name the mutation
◉What are the types of mutations? Answer: silent, missense,
nonsense, frameshift
◉what type of DNA damage does each repair pathway fix? Answer:
base excision - single nucleotide, nucleotide excision repair -
multiple nucleotides, missmatch - mistakes made in DNA replication,
homologous recombination/nonhomologous end joining - double
stranded breaks
◉what are the steps of excision repair? Answer: Recognize damage,
cut damage out, recreate DNA strand, glue DNA strand back together
◉what are the steps of mismatch repair? Answer: Remove
mismatched base, try again
◉what are the steps of homologous recombination and
nonhomologous end joining? Answer: HR uses DNA from unbroken
strand to fix broken strand, NHEJ reconnects broken pieces, may
have pieces missing
◉what are the steps of PCR? Answer: denature, anneal,
elongation/extension
, ◉how do we denature DNA in PCR? Answer: heat to 95 degrees C to
separate DNA strands
◉how do we anneal DNA? Answer: primers base pair with DNA
strands
◉how do we elongation/extend DNA? Answer: DNA polymerase
attach primers and synthesize new DNA strands
◉what are the components of PCR? Answer: target DNA, heat stable
DNA polymerase, nucelotides (dNTP), primers
◉how are primers used to assist in a PCR reaction? Answer:
Primers allow DNA polymerase to bind to target DNA
◉how do you calculate the number of copies of DNA produced by
specific number of PCR cycles? Answer: Each cycle produces
doubles the amount of DNA
◉how does PCR compare to normal DNA replication in the cell?
Answer: RNA primers used instead of DNA in normal replication.
Helicase enzymes separate DNA strands instead of heat in normal
replication. DNA polymerase is not heat stable in normal replication.
