Genetic Mutations (Bio Lab Final)
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Errors in DNA or mutations that don't get repaired, either through the mismatch-repair or through
excision repair mechanisms that are present in organisms, will remain in the DNA of the cells
where they arose. - CORRECT ANSWER -
If you accumulate multiple mutations that affect cell cycle controls -- factors that control rate of
cell division/mitosis, and the cell no longer responds to normal cues for cell division, you have a
cell, or group of cells that are growing out of control -- are malignant, or cancerous. There are
many environmental toxins and mutagens that can increase rates of mutation. Prolonged
exposure to these mutagenic agents will increase your likelihood of getting cancer as you age.
For example, the toxins associated with smoking have been proven to cause lung cancer.
Ultraviolet light causes the formation of pyrimidine dimers in the DNA of cells (usually skin
cells), and with prolonged and/or extensive exposure, increases the risk of developing skin
cancer. - CORRECT ANSWER -
G1 checkpoint - CORRECT ANSWER - involves sensing of environmental conditions. If
energy levels are low, the cell may arrest in G1 for a period of time
DNA replication -- the S phase of the cell cycle, requires a substantial energy investment. The
cell will also arrest in G1 if there are mutagenic agents present and the cell is exposed. During
DNA replication, the DNA molecule is more exposed, and more susceptible to the presence of
mutagenic agents. Preventing the cell from entering the S phase protects the DNA from exposure
to these mutagens. - CORRECT ANSWER -
Pregnant women - CORRECT ANSWER - cautioned to avoid certain medications, and
environmental exposure to harmful radiation and chemicals. Embryonic development is
associated with very rapid cell division and various developmental processes. DNA replication is
taking place continually, especially in the first trimester.
A karyotype - CORRECT ANSWER - -analysis of the chromosomes of a cell.
, -can be done prenatally or postnatally, to determine if there are chromosomal abnormalities in
the affected individual
-slight increase in risk of miscarriage when fetal karyotyping
-can detect alterations in chromosome structure.
aneuploidy - CORRECT ANSWER - -the presence of an extra chromosome (three
homologues -- also known as trisomy) or the absence of one of the homologues (monosomy)
-results from a failure during meiosis (Either the homologues fail to separate in Meiosis I, or the
sister chromatids fail to separate in Meiosis II)
Aneuploidy of the sex chromosomes - CORRECT ANSWER - -most common
-If a person has an extra X chromosome, it is inactivated as a Barr body
-a person can survive with only one X chromosome
Aneuploidies to know - CORRECT ANSWER - Chromosome 21 (Down's
Syndrome/autosome)
Chromosome 15 (Patau's syndrome/autosome)
Chromosome 18 (Edward's Syndrome/autosome) (can affect male/females)
Aneuploid of all other autosomes results in embryonic death.
Chromosomes are lined up based on size and banding pattern in which of the following
procedures? - CORRECT ANSWER - karyotyping
A deletion in the short arm of chromosome 15 would be detected in karyotyping. - CORRECT
ANSWER - true
Nondisjunction - CORRECT ANSWER - homologues failure to separate or sister chromatids
fail to separate
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Errors in DNA or mutations that don't get repaired, either through the mismatch-repair or through
excision repair mechanisms that are present in organisms, will remain in the DNA of the cells
where they arose. - CORRECT ANSWER -
If you accumulate multiple mutations that affect cell cycle controls -- factors that control rate of
cell division/mitosis, and the cell no longer responds to normal cues for cell division, you have a
cell, or group of cells that are growing out of control -- are malignant, or cancerous. There are
many environmental toxins and mutagens that can increase rates of mutation. Prolonged
exposure to these mutagenic agents will increase your likelihood of getting cancer as you age.
For example, the toxins associated with smoking have been proven to cause lung cancer.
Ultraviolet light causes the formation of pyrimidine dimers in the DNA of cells (usually skin
cells), and with prolonged and/or extensive exposure, increases the risk of developing skin
cancer. - CORRECT ANSWER -
G1 checkpoint - CORRECT ANSWER - involves sensing of environmental conditions. If
energy levels are low, the cell may arrest in G1 for a period of time
DNA replication -- the S phase of the cell cycle, requires a substantial energy investment. The
cell will also arrest in G1 if there are mutagenic agents present and the cell is exposed. During
DNA replication, the DNA molecule is more exposed, and more susceptible to the presence of
mutagenic agents. Preventing the cell from entering the S phase protects the DNA from exposure
to these mutagens. - CORRECT ANSWER -
Pregnant women - CORRECT ANSWER - cautioned to avoid certain medications, and
environmental exposure to harmful radiation and chemicals. Embryonic development is
associated with very rapid cell division and various developmental processes. DNA replication is
taking place continually, especially in the first trimester.
A karyotype - CORRECT ANSWER - -analysis of the chromosomes of a cell.
, -can be done prenatally or postnatally, to determine if there are chromosomal abnormalities in
the affected individual
-slight increase in risk of miscarriage when fetal karyotyping
-can detect alterations in chromosome structure.
aneuploidy - CORRECT ANSWER - -the presence of an extra chromosome (three
homologues -- also known as trisomy) or the absence of one of the homologues (monosomy)
-results from a failure during meiosis (Either the homologues fail to separate in Meiosis I, or the
sister chromatids fail to separate in Meiosis II)
Aneuploidy of the sex chromosomes - CORRECT ANSWER - -most common
-If a person has an extra X chromosome, it is inactivated as a Barr body
-a person can survive with only one X chromosome
Aneuploidies to know - CORRECT ANSWER - Chromosome 21 (Down's
Syndrome/autosome)
Chromosome 15 (Patau's syndrome/autosome)
Chromosome 18 (Edward's Syndrome/autosome) (can affect male/females)
Aneuploid of all other autosomes results in embryonic death.
Chromosomes are lined up based on size and banding pattern in which of the following
procedures? - CORRECT ANSWER - karyotyping
A deletion in the short arm of chromosome 15 would be detected in karyotyping. - CORRECT
ANSWER - true
Nondisjunction - CORRECT ANSWER - homologues failure to separate or sister chromatids
fail to separate
