JMU BIO 140 EXAM 1 PRACTICE SCRIPT 2026
TESTED QUESTIONS WITH ANSWERS
◉ What percent of protein coding portion of human genome?
Answer: 2.5%
◉ What are germ line cells? Answer: eggs and sperm
◉ What are somatic cells? Answer: all other cells in the body
◉ What is important for germ line mutations? Answer: rate per
genome per generation
◉ What is important for somatic cells mutations? Answer: mutation
per round of replication
◉ What is cancer? Answer: an accumulation of change in somatic
cells
◉ The accumulation of three successive mutation in a lineage of
colon cells results in what? Answer: malignant colon cancer
,◉ Define genetic risk factors Answer: any mutations that increases
the risk of disease
◉ What are the genes for colon cancer? Answer: APC, Ras, p53
◉ What are the genes for breast cancer? Answer: BRCA1 and BRCA2
◉ What is a common environmental risk factors for skin cancer?
Answer: UV light from sunlight and tanning beds
◉ What happens if mutations not fixed? Answer: it becomes present
in the cell lineage
◉ Define synonymous mutation Answer: a nucleotide substitution
that does not change that amino acid
◉ Define nonsynonymous mutation Answer: a nucleotide
substitution that chances the amino acid
◉ Define nonsense mutation Answer: a nucleotide substitution that
creates a stop codon
◉ What mutation can result in the loss of a codon? Answer: deletion
of three nucleotide
,◉ What mutation can result in the addition of a codon? Answer:
insertion of three nucleotides
◉ Define frameshift mutation Answer: an insertion or deletion that
is not exact multiple of three nucleotide changes the reading frame
of translation
◉ Define missense mutation Answer: changes an amino acid to a
different amino acid
◉ Define silent mutation Answer: non change to the amino acid
◉ Define frameshift mutation Answer: an insertion or deletion that
changes the reading frame
◉ Define transposable elements Answer: elements move to disrupt
the normal function of a gene
◉ Define chromosomal mutations Answer: mutation on a large scale
◉ How is a gene family created? Answer: duplication then
divergence
, ◉ Define chromosomal inversion Answer: chromosome
rearrangement in which a segment of a chromosome is reversed end
to end
◉ Define reciprocal translocation Answer: an exchange of material
between nonhomologous chromosomes.
◉ What are the types of DNA damage? Answer: -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? Answer: UV light
◉ What occurs during replication is the polymerase misses a
mistake? Answer: mismatch repair
◉ How does mismatch repair occur? Answer: -MutS recognizes the
mismatched bases and initiates repair
-MutL and MutH proteins are recruited and MutH breaks the
backbone
-Exonuclease removes successive nucleotides
TESTED QUESTIONS WITH ANSWERS
◉ What percent of protein coding portion of human genome?
Answer: 2.5%
◉ What are germ line cells? Answer: eggs and sperm
◉ What are somatic cells? Answer: all other cells in the body
◉ What is important for germ line mutations? Answer: rate per
genome per generation
◉ What is important for somatic cells mutations? Answer: mutation
per round of replication
◉ What is cancer? Answer: an accumulation of change in somatic
cells
◉ The accumulation of three successive mutation in a lineage of
colon cells results in what? Answer: malignant colon cancer
,◉ Define genetic risk factors Answer: any mutations that increases
the risk of disease
◉ What are the genes for colon cancer? Answer: APC, Ras, p53
◉ What are the genes for breast cancer? Answer: BRCA1 and BRCA2
◉ What is a common environmental risk factors for skin cancer?
Answer: UV light from sunlight and tanning beds
◉ What happens if mutations not fixed? Answer: it becomes present
in the cell lineage
◉ Define synonymous mutation Answer: a nucleotide substitution
that does not change that amino acid
◉ Define nonsynonymous mutation Answer: a nucleotide
substitution that chances the amino acid
◉ Define nonsense mutation Answer: a nucleotide substitution that
creates a stop codon
◉ What mutation can result in the loss of a codon? Answer: deletion
of three nucleotide
,◉ What mutation can result in the addition of a codon? Answer:
insertion of three nucleotides
◉ Define frameshift mutation Answer: an insertion or deletion that
is not exact multiple of three nucleotide changes the reading frame
of translation
◉ Define missense mutation Answer: changes an amino acid to a
different amino acid
◉ Define silent mutation Answer: non change to the amino acid
◉ Define frameshift mutation Answer: an insertion or deletion that
changes the reading frame
◉ Define transposable elements Answer: elements move to disrupt
the normal function of a gene
◉ Define chromosomal mutations Answer: mutation on a large scale
◉ How is a gene family created? Answer: duplication then
divergence
, ◉ Define chromosomal inversion Answer: chromosome
rearrangement in which a segment of a chromosome is reversed end
to end
◉ Define reciprocal translocation Answer: an exchange of material
between nonhomologous chromosomes.
◉ What are the types of DNA damage? Answer: -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? Answer: UV light
◉ What occurs during replication is the polymerase misses a
mistake? Answer: mismatch repair
◉ How does mismatch repair occur? Answer: -MutS recognizes the
mismatched bases and initiates repair
-MutL and MutH proteins are recruited and MutH breaks the
backbone
-Exonuclease removes successive nucleotides
