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AP Biology – Unit 3 – Genetics Review
Name:
Outcome:
Big Idea 3 – Living systems store, transmit, receive and respond to
information essential to life processes. Includes all of 3A, most of 3B, some
of 3C, 3D, and 3E
Multiple Choice
1. Noneukaryotic (prokaryotic) organisms have ___________
chromosomes and eukaryotic organisms have ______________
chromosomes bound to histones.
a) More; less
b) Multiple linear; circular
c) Circular; multiple linear
d) Circular; circular
2. Prokaryotes, viruses and eukaryotes contain _________; small extrachromosomal, double-stranded and circular DNA molecules.
a) ribosomes
b) plasmids
c) flagella
d) chromosomes
3. The individual(s) who is/were responsible for synthesizing data from
the work of Rosalind Franklin and Maurice Wilkins to come up with the
double-helix structure of DNA is/were named:
a) Charles Darwin
b) Francis Crick and James Watson
c) Theodor Schwann
d) Gregor Mendel
4. Nucleotide base pairings C (cytosine), T (thymine), and U (uracil) are
________ having a ______ ring structure.
a) purines, single
b) pyrimidines, single
c) purines, double
d) pyrimidines, double
5. Translation of the mRNA occurs in the __________ of a cell with a
ribosome.
a) cell membrane
b) nucleus
c) golgi apparatus
d) cytoplasm
6. Three steps of translation, in order, are (use numbers 1-start, 3-end):
_) initiation
_) manipulation
_) termination
_) elongation
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7. _____ code for particular amino acids and occur in groups of ______.
a) genes; three
b) codons; three
c) traits; two
d) codons; two
8. Interphase of the cell cycle includes the stages (circle those that
apply).
a) G1 - growth
b) S – DNA Synthesis
c) G2 – preparation for mitosis
d) Mitosis
9. Which of the following “debunks” simple Mendelian genetics?
a) incomplete dominance
b) codominance
c) multiple alleles coding for traits
d) recessive alleles
10.
The last three generations of Petlak have had two boys, which
law/concept of Mendel’s does this critique,
a) law of segregation
b) independent assortment
c) patterns of inheritance (consistent differences in expected
probabilities of phenotypes)
d) recessive traits
11.
Traits residing on X chromosomes in humans are called
a) Somatic
b) Autosomes
c) Alleles
d) sex-linked
12.
Mitochondrial DNA is always passed on from the _______, as
part of the theory of “mitochondrial Eve”.
a) egg
b) sperm
c) chromosome 1
d) y chromosome
13.
If a gene codes for a protein that is required for hair growth, the
activation of this gene would result in a change in the individuals
_________, even though the __________ doesn’t change.
a) genotype, phenotype
b) phenotype, genotype
c) karyotype, phenotype
d) karyotype, genotype
Short Answer
1. What are the molecule(s) responsible for transmission of genetic
information from one generation to the next that contains genes?
What do these molecules ultimately code for?
DNA and RNA – proteins!
2. Describe general similarities and differences in the structure and how
that correlates to the functions of DNA and RNA (consider basepairing, strandedness, and types of sugar making up their structures).
Single versus double helix strands, CG/AT versus CG/AU, ribose versus
deoxyribose.
3. What does it mean when we say that DNA replication occurs bidirectionally (reference leading versus lagging strands in your answer
– and what is the name of the fragment created in the lagging
strand)?
Leading strand is processed from 3’ to 5’ away from the fork while
Okazaki fragments are made on the lagging strand which is processed
in the 5’ to 3’ towards the fork.
4. Given that viruses are composed of and use RNA and an enzyme called
reverse transcriptase, how might they replicate using the cells of
other organisms?
After inserting their RNA into the cell – the enzyme uses the viral RNA
to transcript itself into the DNA of the cell – after which it will be
translated and produced.
5. List four types of RNA and how they differ from one another in
function.
mRNA carries information from DNA to ribosome
tRNA bonds to specific amino acids and delivers to mRNA in ribosome
to create a peptide!
rRNA are the building blocks of ribosomes
miRNA regulate gene expression by interfering with translation of
mRNA
6. What are two modifications mRNA receives by enzymes after it is
transcripted from the DNA – what do these modifications do?
cap/tail (provides stability for mRNA), excision of introns (removes
“useless” coding)
7. **Through describing either MPF or PDGF outline how the cell cycle
has certain controls or checkpoints. How do cyclins and cyclindependent kinases also influence the cell cycle? If a cell stops dividing,
can it become triggered to start again?
8. **Summarize mitosis including terms like diploid as well as the
functions each may serve.
Mitosis occurs after DNA replication producing two identical cells – for
growth, repair, and asexual reproduction. Chromosomes replicate,
align and separate.
9. **Summarize meiosis including terms like haploid, diploid and crossing
over as well as the functions of the cells created by meiosis.
two gametes are created (haploid). Meant for reproduction. Similar to
mitosis, but homologues overlap and exchange info in crossing over
and separate in new combinations of information.
10.
How do repressors, activators, or inducers affect gene
expression? Are genes always on?
A repressor binds to locations on RNA that allow to not be synthesized.
An activator allows or promotes the transcription of a gene.
Presence of an inducer can promote or stop production of a gene.
11.
Mutations can be good or bad and lead to genetic variation.
What determines whether a mutation that leads to a change is good or
bad? Provide an example of a good mutation for bacteria (consider
hand sanitizer usage).
Environment.
12.
How can an error in mitosis or meiosis lead to phenotypic change
in offspring? How might natural selection affect this individual?
presence or absence of chromosomes = changes in
appearance/performance may lead to a lack of ability to reproduce.
13.
How do errors or alterations in the process of transcription,
translation, and gene expression actually increase variation or changes
in populations? Viruses lack any sort of error-correcting mechanism,
what could this mean about its variation?
the mistakes lead to new phenotypes and genetic combinations that
may strengthen diversity in the population.
Much more mutations and variation.
Long Answer
1. A. Including at least four enzymes, outline the process of
semiconservative DNA replication and RNA production for protein
synthesis in eukaryotes (5).
ligase (recombines DNA), helicase (splits DNA), RNA/DNA polymerase
(synthesizes nucleotide base pairs in transcription), topoisomerase
(unwinds DNA from histones). After the mRNA is created, tRNA finds
associated amino acids and brings it to the ribosome to synthesize a
protein.
B. Provide detail as to how errors in the different steps of this process
can lead to cancer and what may cause these errors (5).
2. A. Describe the cause of Down’s Syndrome (is this a genetic or
chromosomal disorder?)
B. How does probability, segregation, independent assortment,
distance of genes on chromosomes connect to genotypes and
phenotypes passing from parents to offspring.
C. Given what you know about A. and B. should individuals carrying
reproductive abnormalities such as this be allowed to reproduce? Why
or why not? What are the ethical/societal/evolutionary implications of
your decision?
3. pet protein sequence is a made-up enzyme (protein sequence)
responsible for helping individuals named Mr. Logan Petlak to process
the awesome that he consumes on an hourly basis. The operon for pet
is found on chromosome 1. Using the graph below, answer the
following (10).
Concentration of pet protein sequence (ppm)
Concentration of pet protein sequence in blood over time
elapsed after consuming awesome (ppm)
4
3.5
3
2.5
2
1.5
1
0.5
0
1
2
3
4
5
6
7
8
Time Elapsed after Consuming Awesome (minutes)
A. Provide an explanation for the increase in the presence of the pet
protein sequence in the blood. Include why it became present and
why it may not have been present before.
B. Predict and justify why the protein ceased to increase after four
minutes and then proceeded to decline.
C. Estimate the concentration change from minutes 2 to 3 and 3 to 4
and provide an explanation for the difference.
D. Propose one advantage for their being a concentration of 0ppm of
pet at minute 0 and minute 8.
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