JMU BIO 140 UPDATED EVALUATION EXAMS
QUESTIONS AND ANSWERS SURE A+
✔✔What percent of protein coding portion of human genome? - ✔✔2.5%
✔✔What are germ line cells? - ✔✔eggs and sperm
✔✔What are somatic cells? - ✔✔all other cells in the body
✔✔What is important for germ line mutations? - ✔✔rate per genome per generation
✔✔What is important for somatic cells mutations? - ✔✔mutation per round of replication
✔✔What is cancer? - ✔✔an accumulation of change in somatic cells
✔✔The accumulation of three successive mutation in a lineage of colon cells results in
what? - ✔✔malignant colon cancer
✔✔Define genetic risk factors - ✔✔any mutations that increases the risk of disease
✔✔What are the genes for colon cancer? - ✔✔APC, Ras, p53
,✔✔What are the genes for breast cancer? - ✔✔BRCA1 and BRCA2
✔✔What is a common environmental risk factors for skin cancer? - ✔✔UV light from
sunlight and tanning beds
✔✔What happens if mutations not fixed? - ✔✔it becomes present in the cell lineage
✔✔Define synonymous mutation - ✔✔a nucleotide substitution that does not change
that amino acid
✔✔Define nonsynonymous mutation - ✔✔a nucleotide substitution that chances the
amino acid
✔✔Define nonsense mutation - ✔✔a nucleotide substitution that creates a stop codon
✔✔What mutation can result in the loss of a codon? - ✔✔deletion of three nucleotide
✔✔What mutation can result in the addition of a codon? - ✔✔insertion of three
nucleotides
✔✔Define frameshift mutation - ✔✔an insertion or deletion that is not exact multiple of
three nucleotide changes the reading frame of translation
✔✔Define missense mutation - ✔✔changes an amino acid to a different amino acid
✔✔Define silent mutation - ✔✔non change to the amino acid
✔✔Define frameshift mutation - ✔✔an insertion or deletion that changes the reading
frame
✔✔Define transposable elements - ✔✔elements move to disrupt the normal function of
a gene
✔✔Define chromosomal mutations - ✔✔mutation on a large scale
✔✔How is a gene family created? - ✔✔duplication then divergence
✔✔Define chromosomal inversion - ✔✔chromosome rearrangement in which a segment
of a chromosome is reversed end to end
✔✔Define reciprocal translocation - ✔✔an exchange of material between
nonhomologous chromosomes.
✔✔What are the types of DNA damage? - ✔✔-single-stranded break in DNA backbone
, -cross-linked thymine bases
-missing base (thymine dimers)
-bulky side group attached to a base
-double-stranded break in the DNA
✔✔What usually is the cause for thymine dimers? - ✔✔UV light
✔✔What occurs during replication is the polymerase misses a mistake? - ✔✔mismatch
repair
✔✔How does mismatch repair occur? - ✔✔-MutS recognizes the mismatched bases
and initiates repair
-MutL and MutH proteins are recruited and MutH breaks the backbone
-Exonuclease removes successive nucleotides
-DNA polymerase fills in the missing nucleotides and DNA ligase joins the backbones
✔✔What occurs in order to fix cytosine from uracil? - ✔✔deamination
✔✔How is the uracil replaced? - ✔✔base excision repair
✔✔What are the steps of replacing a uracil with cytosine? - ✔✔-uracil signals the need
to repair
-DNA uracil glycosylase cleaves the uracil
-AP endonuclease cleaves the backbone and removed the sugar
-Other enzymes close the gap by new DNA synthesis
✔✔What are the steps of nucleotide excision repair? - ✔✔-one or more damaged bases
signal for repair
-an enzyme cleaves the DNA backbone at sites flanking the damage
-region with damages bases is removed
-gap is filled by new DNA synthesis
✔✔What is an effect of defects in mismatch repair? - ✔✔colon cancer
✔✔What is an effect of defects in the nucleotide excision repair? - ✔✔xeroderma
pigmentosum
✔✔Why are mutations helpful? - ✔✔-genetic variation
-natural selection
✔✔Define mutations - ✔✔any heritable change in the genetic material, usually a
change in the nucleotide sequence
✔✔Define a mutation hotspot - ✔✔a site in the genome that is especially mutable
QUESTIONS AND ANSWERS SURE A+
✔✔What percent of protein coding portion of human genome? - ✔✔2.5%
✔✔What are germ line cells? - ✔✔eggs and sperm
✔✔What are somatic cells? - ✔✔all other cells in the body
✔✔What is important for germ line mutations? - ✔✔rate per genome per generation
✔✔What is important for somatic cells mutations? - ✔✔mutation per round of replication
✔✔What is cancer? - ✔✔an accumulation of change in somatic cells
✔✔The accumulation of three successive mutation in a lineage of colon cells results in
what? - ✔✔malignant colon cancer
✔✔Define genetic risk factors - ✔✔any mutations that increases the risk of disease
✔✔What are the genes for colon cancer? - ✔✔APC, Ras, p53
,✔✔What are the genes for breast cancer? - ✔✔BRCA1 and BRCA2
✔✔What is a common environmental risk factors for skin cancer? - ✔✔UV light from
sunlight and tanning beds
✔✔What happens if mutations not fixed? - ✔✔it becomes present in the cell lineage
✔✔Define synonymous mutation - ✔✔a nucleotide substitution that does not change
that amino acid
✔✔Define nonsynonymous mutation - ✔✔a nucleotide substitution that chances the
amino acid
✔✔Define nonsense mutation - ✔✔a nucleotide substitution that creates a stop codon
✔✔What mutation can result in the loss of a codon? - ✔✔deletion of three nucleotide
✔✔What mutation can result in the addition of a codon? - ✔✔insertion of three
nucleotides
✔✔Define frameshift mutation - ✔✔an insertion or deletion that is not exact multiple of
three nucleotide changes the reading frame of translation
✔✔Define missense mutation - ✔✔changes an amino acid to a different amino acid
✔✔Define silent mutation - ✔✔non change to the amino acid
✔✔Define frameshift mutation - ✔✔an insertion or deletion that changes the reading
frame
✔✔Define transposable elements - ✔✔elements move to disrupt the normal function of
a gene
✔✔Define chromosomal mutations - ✔✔mutation on a large scale
✔✔How is a gene family created? - ✔✔duplication then divergence
✔✔Define chromosomal inversion - ✔✔chromosome rearrangement in which a segment
of a chromosome is reversed end to end
✔✔Define reciprocal translocation - ✔✔an exchange of material between
nonhomologous chromosomes.
✔✔What are the types of DNA damage? - ✔✔-single-stranded break in DNA backbone
, -cross-linked thymine bases
-missing base (thymine dimers)
-bulky side group attached to a base
-double-stranded break in the DNA
✔✔What usually is the cause for thymine dimers? - ✔✔UV light
✔✔What occurs during replication is the polymerase misses a mistake? - ✔✔mismatch
repair
✔✔How does mismatch repair occur? - ✔✔-MutS recognizes the mismatched bases
and initiates repair
-MutL and MutH proteins are recruited and MutH breaks the backbone
-Exonuclease removes successive nucleotides
-DNA polymerase fills in the missing nucleotides and DNA ligase joins the backbones
✔✔What occurs in order to fix cytosine from uracil? - ✔✔deamination
✔✔How is the uracil replaced? - ✔✔base excision repair
✔✔What are the steps of replacing a uracil with cytosine? - ✔✔-uracil signals the need
to repair
-DNA uracil glycosylase cleaves the uracil
-AP endonuclease cleaves the backbone and removed the sugar
-Other enzymes close the gap by new DNA synthesis
✔✔What are the steps of nucleotide excision repair? - ✔✔-one or more damaged bases
signal for repair
-an enzyme cleaves the DNA backbone at sites flanking the damage
-region with damages bases is removed
-gap is filled by new DNA synthesis
✔✔What is an effect of defects in mismatch repair? - ✔✔colon cancer
✔✔What is an effect of defects in the nucleotide excision repair? - ✔✔xeroderma
pigmentosum
✔✔Why are mutations helpful? - ✔✔-genetic variation
-natural selection
✔✔Define mutations - ✔✔any heritable change in the genetic material, usually a
change in the nucleotide sequence
✔✔Define a mutation hotspot - ✔✔a site in the genome that is especially mutable
