Bio 104 2002 Test 3 Answers Stark

1. What is different between a bacteriophage and HIV (human immunodeficiency virus)?
(a) whether DNA or RNA is the genetic material
(b) whether hereditary material alone or additional components enter the cell
(c) whether or not there is cell lysis
(d) whether they are made up of hereditary material plus protein alone or have additional molecules.
*(e) all of the above

2. The codes for leucine include CUU, CUC, CUA, and CUG. A nucleotide substitution in the third position of the codon would
*(a) have no effect on the final protein.
(b) have no effect on the exact mRNA sequence.
(c) cause the protein synthesis to stop prematurely.
(d) not even change which tRNA molecule recognizes the codon.
(e) result in an amino acid substitution.

3. Which enzyme is the hallmark of HIV (human immunodeficiency virus) that causes AIDS (acquired immunodeficiency virus)?
(a) primase.
(b) nuclease.
(c) telomerase.
(d) hemoglobin.
*(e) reverse transcriptase.

4. Codons such as CUG would be found
*(a) on the mRNA.
(b) on an antibody.
(c) in the restriction endonuclease.
(d) on the ribosome.
(e) on the template DNA.

5. Which identifies a protein using an antibody?
(a) the PCR reaction
(b) allolactose
(c) RFLP mapping
(d) chromosome walking
*(e) western blotting

6. DNA polymerase synthesizes a new molecule
(a) in the helix turn helix direction.
*(b) in the 5' to 3' direction.
(c) of RNA.
(d) in the 5' cap to poly(A) tail direction.
(e) in the intron to exon direction.

7. What would be a difference between cDNA and genomic DNA?
(a) Only a genomic DNA library would be different from tissue to tissue.
(b) Only a cDNA library would have all the genes.
*(c) Only cDNA would lack introns.
(d) Only genomic DNA is made from mRNA.
(e) Nothing - they are the same.

8. Which of the following has plasmids?
(a) HIV
(b) flu
*(c) E. coli
(d) small pox
(e) T4

9. PCR is used to
(a) determine the sizes of different restriction fragments.
(b) insert a new gene in gene therapy
*(c) make multiple copies of a gene of interest.
(d) identify protein in a blot.
(e) get rid of p53.

10. In the fruit fly Drosophila, a hunk of DNA might jump into its DNA, perhaps disrupting a gene or bringing in a new gene to make a transgenic animal. Such a hunk might be called a
(a) blot.
(b) plasmid.
*(c) transposon.
(d) capsid.
(e) prion.

11. Nonsense mutations are
(a) codons changed to start.
*(b) codons changed to stop.
(c) codons changed to codons for another amino acid.
(d) mutations in the position that defines degeneracy of DNA.
(e) jumping genes.

12. One thing that is unique to gene transcription in bacteria is
*(a) several enzymes might be coded for by one mRNA.
(b) introns are spliced out.
(c) there is processing of a pre-mRNA to mRNA before mRNA leaves the nucleus.
(d) genetic information is carried by RNA that is transcribed to DNA.
(e) the hereditary information is carried by proteins.

13. Vaccination confers active immunity by
*(a) stimulating your immune system to make antibodies.
(b) stimulating your immune system to make antigens.
(c) stimulating your immune system to make prions.
(d) stimulating your immune system to make transposons.
(e) giving a person antibodies made by another person when (s)he overcame the disease.

14. Which is used to fingerprint DNA that is found at the scene of a crime?
(a) a cDNA library.
(b) an immunoblot.
(c) a northern blot
*(d) a Southern blot.
(e) a western blot.

15. The genetic code for Met (the amino acid methionine), AUG, is unique because
(a) it is a DNA sequence.
(b) it is the sort of palindrome that is cut by a restriction enzyme.
(c) it is also the binding site for a helix turn helix molecule.
*(d) it is also the start codon.
(e) it is also the stop codon.

16. A disease-causing allele of a gene can be mapped to a "marker" that is a nearby alteration in DNA sequence called a(n)
(a) autoradiogram.
(b) PCR primer.
(c) G protein.
(d) hybridization.
*(e) RFLP (restriction fragment length polymorphism).

17. The first vaccination, in the late 1700's was against
(a) polio.
(b) Asian flu.
*(c) small pox.
(d) a retrovirus.
(e) E. coli.

18. The central dogma of cell biology
(a) postulates that protein is transcribed directly from DNA.
*(b) runs in reverse with the virus that causes AIDS.
(c) applies to how one DNA strand has the information to synthesize the other strand.
(d) states that amino acid sequences are translated into nucleotide sequences.
(e) explains the plasmid.

19. Introns
(a) are "jumping genes" with inverted repeats at their ends.
(b) are the type of virus that "eat" bacteria.
(c) are only found in prokaryotes.
*(d) are the parts of eukaryotic pre-mRNA that are spliced out to make mRNA.
(e) cause mad cow disease.

20. In prokaryotes, transcription
(a) makes a molecule with introns and exons.
(b) makes proteins.
(c) makes transcription factors.
*(d) makes mRNA.
(e) takes place in the nucleus.

21. The terms "motif" (leucine zipper motif) and "factor" (transcription factor) apply to
(a) the particular cuts made by restriction endonucleases (like EcoR1).
(b) circles of DNA (such as one coding for ampicillin resistance).
(c) sequences of DNA (such as those in the promoter).
(d) the way strands with complementary base pairs stick (like when you probe to identify a cloned gene).
*(e) proteins (such as proteins with DNA binding domains).

22. A TATA box would typically be found in
(a) a polysome.
(b) the primary transcript.
(c) the intron.
(d) the coding sequence.
*(e) the promoter.

23. A ligase would be used in
(a) control of gene transcription.
(b) synthesis of DNA from the hereditary molecule in the HIV (human immunodeficiency virus).
(c) western blotting.
*(d) lagging strand replication.
(e) cutting open a plasmid to prepare for cloning a gene.

24. In the 1940's, Avery and others showed DNA was the important part of smooth bacterial extract that made rough bacteria pathogenic in Griffith's experiment. The phenomenon Griffith demonstrated is called
*(a) transformation.
(b) conjugation.
(c) cloning.
(d) hybridization.
(e) operon regulation.

25. The vast diversity of antibodies is mediated by a unique mechanism found in differentiated B lymphocytes:
*(a) rearrangement of the antibody gene's DNA.
(b) structural organization of the protein as an alpha helix.
(c) phosphorylation of tyrosine residues by a tyrosine kinase.
(d) binding of GTP.
(e) incorporation of zinc into zinc-fingers.

26. [A] is the beginning of the mRNA while [B] is the beginning of its template of DNA.
(a) [A] 3', [B] 3'
(b) [A] 5', [B] 5'
(c) [A] 3', [B] 5'
*(d) [A] 5', [B] 3'
(e) none of the above

27. Anticodon is a term applied to
(a) ribosomal subunits.
(b) the DNA template.
*(c) aminoacyl-tRNA.
(d) the exon.
(e) the poly-A tail.

28. Histones are
(a) packaged in retroviruses.
(b) the circles of DNA into which genes are cloned.
*(c) proteins associated with DNA.
(d) antibodies.
(e) transposons.

29. A Nobel Prize relates to mad cow disease, caused by a
(a) virus.
*(b) protein.
(c) bacterium.
(d) plasmid.
(e) transposon.

30. Reverse transcriptase would work on [A] to form [B].
(a) [A] bacteria; [B] bacteriophage
(b) [A] pre-mRNA; [B] mRNA
(c) [A] mRNA; [B] protein
(d) [A] DNA; [B] PCR reaction products
*(e) [A] RNA; [B] DNA

31. If the sequences of bases along the template strand of DNA is A-G-A-T, what is the sequence along the mRNA strand?
(a) A-G-A-T
*(b) U-C-U-A
(c) A-T-C-T
(d) A-G-A-U
(e) U-A-G-A

32. The term "oncogene" applies to
(a) the kind of genes regulated by an operator.
*(b) genes involved in cancer.
(c) the way genes are altered in gene therapy.
(d) the genes that are coded in cDNA
(e) "beads on a string."

33. Sickle cell anemia is a
*(a) missense mutation.
(b) nonsense mutation.
(c) frameshift.
(d) thymine dimer.
(e) result of telomerase.

34. What happens when bacteriophage T2 infects a bacterium?
(a) Phage RNA enters the cell.
*(b) Only viral DNA enters the bacterium.
(c) Only viral protein enters the bacterium.
(d) The entire virus, enzymes and membranes and all, enter.
(e) The virus injects a poison into the bacterium to kill it.

35. An Okasaki fragment is
(a) a transcription factor.
(b) the portion of the pre-mRNA that is spliced out.
(c) the 5'-cap.
*(d) one product of DNA polymerase.
(e) one product of RNA polymerase II.

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