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Name ______________________________
DNA Test Study Guide- Honors
Complete the following multiple-choice questions. As we go over the correct responses, make notes for yourself
about the question below it.
______1. The cells that make up the skin of an individual have some functions different from the cells
that make up the liver because
a. all cells have a common ancestor.
b. different cells have different genetic material.
c. environment and past history have no influence on cell function.
X
d. different parts of genetic instructions are used in different types of cells.
Notes: All of your cells have the same DNA (so no to B), Cells do not have ancestors (so A is wrong), The
environment can influence phenotype (so C is not a correct choice), Not ALL genes are expressed in every
cell, only certain genes are expressed in each cell that is what makes them different, so D is the correct
choice.
______2. Fruit flies with the curly-wing trait will develop straight wings if kept at a temperature of
16°C during development and curly wings if kept at 25°C. The best explanation for this
change in the shape of wings is that the
a. genes for curly wings and genes for straight wings are found on different
chromosomes.
b. type of genes present in the fruit fly is dependent upon environmental temperature.
X
c. environment affects the expression of the genes for this trait.
d. higher temperature produces a gene mutation.
Notes: Genes for the same trait are found on the same chromosomes (A is incorrect)
The existence of the gene itself is not dependent upon the environment (B is incorrect)
A mutation would cause a change (something other than curly and straight) (D is incorrect)
The environment can influence how genes are expressed (think twins raised in different parts
of the world). This makes C the correct choice
______3. The production of certain human hormones by genetically engineered bacteria results from
a. inserting a specific group of amino acids into the bacteria.
X
b. combining a portion of the human DNA with the bacterial DNA and inserting this into bacteria.
c. crossing two different species of bacteria.
d. deleting a specific amino acid from human DNA and inserting it into bacterial DNA.
Notes: It is not a specific group of amino acids that are inserted; it is a gene (A is incorrect)
Crossing 2 different species of bacteria will not involve the human hormone at all (C is
incorrect)
Again, it is not amino acids that are manipulated it is a gene (D is incorrect)
In order to produce a human hormone by genetically engineering bacteria, we need to
combine a portion (gene) of human DNA with bacteria DNA to get the bacteria to produce the
human hormone.
______4. Which phrase does not describe cells cloned from a carrot?
a. They are genetically identical.
c. They have the same DNA codes.
X
b. They are produced sexually.
d. They have identical chromosomes.
Notes: Cloned cells are genetically identical (so A is not correct)
Cloned cells do have the same DNA codes (C is not correct)
Cloned cells do have identical chromosomes (D is not correct)
Cloned cells are not produced sexually (through egg and sperm cells) this is why B is correct.
______5. Genes involved in the production of abnormal red blood cells have an abnormal sequence of
a. ATP molecules.
c. sugars.
b. amino acids.
d. bases. XXXX
Notes: Genes are not made from ATP molecules (this is photosynthesis and cell respiration) No A
Genes are not made from sugars (so no C)
Genes that have an abnormal production means that they have an abnormal protein which means
a mutation occurred in their DNA so B is incorrect and D is correct.
______6. Klinefelter’s syndrome is a genetic disorder caused by the presence of an extra chromosome in
the body cells of humans. This extra chromosome occurs in the gamete as a result of
a. an error in the process of cloning.
c. a gene mutation.
X
b. an error in meiotic cell division.
d. replication of a single chromosome during mitosis.
Notes: Cloning has not been accomplished as we currently know in humans (no to A)
A gene mutation messes up one gene, this scenario talks about a chromosomal mutation (no C)
Replication of chromosomes happens normally in single chromosomes before mitosis , mitosis does NOT
involve gametes. (no to D)
In meiosis gametes are formed (sex cells), chromosomes can fail to pull correctly (non disjunction) (This
is why B is correct)
Name the individual subunits on the left and the name of the structure they make on the right.
Amino Acids
Protein
Answer the following.
1. Transcribe the provided DNA strand, and then translate it into a protein using your amino acid chart from
your notes.
DNA strand: TAC-CCG-TTA-CCT-GGC-AAC-GAT-CAC-ATC
MRNA:
AUG-GGC-AAU-GGA-CCG-UUG-CUA-GUG-UAG
Protein:
Met – Gly – Asn – Gly – Pro – Leu – Leu – Val - Stop
Show the following mutations of the above DNA strand and discuss how they would or would not affect
the amino acids found within the protein:
DNA:
TAC – CGG – TTA – CCT – GGC – AAC – GAT – CAC - ATC
A. Point (Substitution): AUG – GCC – AAU – GGA – CCG – UUG – CUA – GUG - UAG
Effect on protein:
Met – Ala – Asn – Gly – Pro – Leu – Leu – Val – Stop (1 amino acid change, so 1
point is changed)
DNA:
B. Silent (Point):
Effect on protein:
TAC – CCC – TTA – CCT – GGC – AAC – GAT – CAC - ATC
AUG – GGG – AAU – GGA – CCG – UUG – CUA – GUG - UAG
Met – Gly – Asn – Gly – Pro – Leu – Leu – Val – Stop (No effect, same exact
protein)
DNA:
C. Nonsense (Point)
Effect on protein:
TAC – CCG – TTA – CCT – GGC - ATC
AUG – GGC – AAU – GGA – CCG - UAG
Met – Gly – Asn – Gly – Pro – Stop
DNA:
D. Frame shift (insertion)
Effect on protein:
TAC – ACC – GTT – ACC – TGG – CAA – CGA – TCA – CAT - C
AUG – UGG – CAA – UGG – ACC – GUU – GCU – AGU - GUA
Met – Trp – Gln – Trp – Thr – Val – Ala – Ser – Val (Entire reading
frame was shifted so now all amino
acids are messed up from where the
insertion occurred, and onwards)
DNA:
E. Frame shift (deletion)
Effect on protein:
TAC – CCG – TT*C – CTG – GCA – ACG – ATC – ACA - TC
AUG – GGC – AAG – GAC – CGU – UGC – UAG – UGU
Met – Gly – Lys – Asp – Arg – Cys – Stop (All amino acids messed up
from the deletion on, and it resulted
in a premature stop codon)
2. Arrange the following structures from largest to smallest. Explain how they are related.
A chromosome
A nucleus
A gene
Largest
Smallest
1. Nucleus: (chromosomes and genes are located in the nucleus)
2. Chromosome: (chromosomes are in the nucleus and genes are
smaller parts of a chromosome)
3. Gene: (Is a smaller part fund on a chromosome)
3. What is a mutation?
A mutation is any change to the DNA code whether it is a good, neutral, or bad change that may or
may not affect phenotype.
4. What is the difference between a gene mutation and a chromosomal mutation?
A gene mutation affects one gene on a chromosome, but a chromosomal mutation affects many
genes on a chromosome.
5. Describe and Draw (using ABCDEF as genes on the chromosome) the following chromosomal mutations:
a. Deletion: This type of chromosomal mutation occurs when a piece of the chromosome breaks off
and is missing.
EX: ABDEF
b. Inversion: This type of chromosomal mutation occurs when a piece breaks off and reinserts
backwards so that the genes are not out of order.
EX: ABCFED
c. Duplication: This type of chromosomal mutation occurs when there is an unequal exchange
between homologous sets and some genes are doubled.
EX: ABCDEFF
d. Nondisjunction: This chromosomal mutation occurs when chromosomes fail to separate equally
during meiosis and some gametes (sex cells) get too many chromosomes. (Trisomy like Down
Syndrome)
EX: ABCDEF ABCDEF ABCDEF (3 OF THE SAME CHROMOSOMES)
e. Translocation: This type of chromosomal mutation occurs when non-homologous sets exchange
pieces. EX: genes from set 17 are on set 1.
EX: ABCDEFWXYZ
6. Describe DNA replication. When does it take place? Where does it take place? What are the steps? What
is the purpose? How is the information in DNA conserved?
DNA Replication is the process of making an identical copy of an organisms DNA. It takes place during
the S phase of the cell cycle. In eukaryotic organisms, it takes place inside the nucleus, in prokaryotes, It
takes place in the cytoplasm. The first step is: The DNA double helix unwinds using an enzyme called
DNA helicase, the second step is: free floating nucleotides match up with the 2 template strands that are
presently separated, the third step is: DNA polymerase bonds and proofreads the 2 semiconservative
strands that were made.
7. Describe transcription. Where does it take place? What are the steps? What is the purpose?
Transcription is the process of changing DNA into mRNA. The end goal will be to make a protein to
express that portion of DNA known as a gene. It takes place in the nucleus in eukaryotic organisms, and
in the cytoplasm of prokaryotic organisms. Steps: a segment of DNA opens up known as a gene, one side
of that DNA is read to make a single strand of mRNA (using base pairing rules with A-U and C-G), DNA
winds back up, RNA polymerase bonds the RNA molecule and proofreads the strand.
8. Describe translation. Where does it take place? What are the steps? What is the purpose?
Translation is the process of building the actual protein from the mRNA strand. This needs to occur to
make proteins to express the genes in our DNA, this is what keeps us alive. It takes place on a ribosome
in both eukaryotic and prokaryotic cells. Steps: mRNA finds a ribsosome, codons are read (3 bases at a
time) by a complimentary tRNA molecule that carries the anticodon. The protein strats when the
universal start codon (Met) is recognized. The tRNA molecule transfers the proper amino acids to the
ribosome so that the protein can be built. Once a stop codon is reached, the process ends, the protein
folds into a special shape and is released to do its job in the living organism.
9. How are transcription and translation similar in all living things?
Prokaryotes and Eukaryotes can carry out the process of transcription because both cell types have DNA
that can change into RNA. Prokaryotes and Eukaryotes can carry out the process of translation because
both cell types have ribosomes, which is where translation takes place.
10. Trace the path of a membrane or secretory protein beginning with the instructions in the nucleus to the
final destination of the product at the cell membrane (trace the flow of the information from beginning to
end)?
Nucleus - Ribosome on RER- Transport Vesicle – Golgi Body – Secretory Vesicle- Cell Membrane (Exocytosis)
11. What is cloning? How can something be cloned? How might cloning be useful?
Cloning is the process of creating a genetically identical copy. It is done naturally by anything that
reproduces through the process of mitosis. It is unnatural when it is performed through nuclear transfer in
sexually producing organisms. The nucleus from the egg cell of a female egg cell is removed, a cell from
the organism to be cloned is fused with the egg cell. The newly combined cells are stimulated to start
mitosis and the embryo is implanted into a host to grow and prepare for “birth.” Cloning is useful to help
with endangered species, and to help with organ transplants (cloning animals so that humans may be able
to use their organs)
12. Use the picture to answer the following questions
13. Circle the band(s) on the gel electrophoresis that would be considered the smallest bands based on their
travel time.
14. Which 2 organisms would be most closely related?
Organisms 1 & 2
15. Describe how scientists can genetically engineer something. What are some benefits of genetic
engineering/gene splicing? What are some negative aspects of genetic engineering?
Genetic Engineering means changing the DNA of an organism. The benefits are to produce large
quantities of medicines (pharming), having a better understanding of how to treat disease in humans by
experimenting with animals, and being able to study gene sequences in living things. Lack of genetic
diversity, population wipeout with disease, affected natural pollinators.
16. What is a GMO? What are the pros and cons to creating GMO’s?
A GMO is a genetically modified organism. Pro’s/Benefits would be to produce a large abundance of
food, to give crops favorable traits like (anti-frost, resistance of pesticides, and to give crops beneficial
nutrients like rice). The negative effects are unknown long-term effects in humans, a decrease to
biodiversity, and transgenic plants pollinating with normal “wild” plants producing a new population of
transgenic offspring.
17. What is gene therapy? How does it help someone to survive a genetic disorder?
Gene Therapy is the replacement of a defective or missing gene, or the addition of a new gene into a
person's genome to treat a disease. This is a promising treatment option for inherited genetic disorders &
certain types of cancers, but it is still in the experimental phase.
18. A = 20% T = 20% C = 30% G = 30%