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1. 1. These structures are always identical:
      1. Sister chromatids
      2. Bases belonging to a base pair
      3. Homologous chromosomes
      4. Strands of a DNA double helix
      5. None of the above

   2. The most compact form of right-handed, double stranded DNA is:
      1. H-form DNA
      2. Z-form DNA
      3. A-form DNA
      4. B-form DNA
      5. None of the above

   3. A B-form double stranded DNA molecule is 100,000 base pairs long. How long in angstroms is the DNA molecule?
      1. 200,000
      2. 100,000
      3. 50,000
      4. 10,000
      5. None of the above

   4. DNA was extracted from a cell in Rosalyn Franklin's large toe. Upon analysis of its base concentration, it was found that 17% of its bases were guanine. What percentage of its bases are thymine?
      1. 83
      2. 66
      3. 33
      4. 0
      5. Cannot be determined from the information given

   5. RNA was extracted from tobacco mosaic virus (a single-stranded RNA virus) particles and it was found that 20% of the bases it contained were cytosine. What percentage of its bases would be adenine?
      1. 80
      2. 60
      3. 33
      4. 0
      5. Cannot be determined from the information given

   6. In the early 1950's, Maurice Wilkins and Rosalyn Franklin used what method to photograph DNA (Watson and Crick deduced the structure of DNA in 1953 through these photographs)?
      1. Autoradiography
      2. X-ray diffraction
      3. Switching cell medium from ¹⁵N to ¹⁴N
      4. CsCl gradient
      5. Silver halide emulsion

2. 7. In the 1960's, Schnos and Inman used autoradiography to show that the origin of chromosomal replication in circular DNA lies between two A-T rich denaturation sites. They then showed when the chromosome reached the theta shaped phase of replication, the replication forks had passed through BOTH A-T rich denaturation sites. What did this classic experiment prove?
      1. Bacterial DNA replicates semiconservatively
      2. Bacterial DNA replicates unidirectionally
      3. Bacterial DNA always replicates 5'--> 3'
      4. Bacterial DNA replicates bidirectionally
      5. Bacterial DNA always has multiple origins of replication

   8. A culture of bacteria is grown for many generations in a medium in which the only available nitrogen is the heavy isotope (¹⁵N). The culture is then switched to a medium containing only ¹⁴N for one generation of growth; it is then returned to a ¹⁵N-containing medium for one final generation of growth. If the DNA from these bacteria is isolated and centrifuged to equilibrium in a CsCl density gradient, how would you predict the DNA to band in the gradient?
      1. 1/1 hybrid
      2. 1/2 hybrid, 1/2 light
      3. 1/2 hybrid, 1/2 heavy
      4. 1/2 light, 1/2 heavy
      5. 1/4 hybrid, 3/4 light

   9. Which of the following enzymes removes RNA primers on the lagging strand during DNA replication?
      1. DNA polymerase I
      2. DNA polymerase II
      3. DNA polymerase III
      4. All of the above
      5. None of the above

   10. The enzyme responsible for joining Okazaki fragments is:
       1. DNA ligase
       2. DNA polymerase I
       3. Primase
       4. DNA polymerase III

3. 11. Transcription in prokaryotes is a process that requires key participants for synthesis. Which of the following may serve as a key participant?
       1. RNA primer
       2. Deoxyribonucleotide triphosphates
       3. Sigma units
       4. All of the above
       5. None of the above

4. You have found the DNA sequence that codes for the ability to play "Hail State" on the kazoo while hopping on one leg. The DNA sequence is as follows:
   5' CTA AGC GTT AGA CAT 3'
   12. What is the complementary pre-mRNA sequence?
       1. 5' GAU UCG CAA UCU GUA 3'
       2. 5' ATG TCT AAC GCT TAG 3'
       3. 5' UAC AGA UUG CGA AUC 3'
       4. 5' AUG UCU AAC GCU UAG 3'
       5. 5' GAT TCG CAA TCT GTA 3'

   13. Which DNA-dependent RNA polymerase would produce this pre-mRNA sequence?
       1. I
       2. II
       3. III

   14. What is the amino acid sequence for the appropriate polypeptide that would be synthesized? SEE GENETIC CODE TABLE BELOW.
       1. Tyr-Thr-Leu-Arg-Ileu
       2. Met-Asp-Ser-Gln-Val
       3. Met-Ser-Asn-Ala-Stop
       4. Asp-Ser-Gln-Ser-Val
       5. Met-Ala-Ser-Asn-Stop

       

5. 15. Which two amino acids have nondegenerate codons? SEE GENETIC CODE TABLE.
       1. met, trp
       2. trp, ser
       3. ser, gln
       4. met, lys
       5. gln, lys

   16. What hypothesis states that the 5' base of an anticodon may loosely bind to its complementary 3' codon base?
       1. Wobble
       2. Termination
       3. Partial degeneracy
       4. Complete degeneracy
       5. Universality

   17. Which of the following tRNA anticodons will bind to the following mRNA codon: 5' CUA 3'? SEE GENETIC CODE TABLE ABOVE.
       1. 5' GAU 3' only
       2. 5' UAG 3' only
       3. 5' UAG 3' or 5' CAG 3'
       4. 5' CAG 3' only
       5. 5' GAU 3' or 5' UAG 3'

6. 18. Which of the following is NOT a possible post-transcriptional point of control of mRNA in eukaryotes?
       1. pre-mRNA may require processing
       2. mRNA must be transported from the nucleus to the cytoplasm
       3. mRNA may be stored in vesicles and secreted when required
       4. mRNA may degrade in the cytoplasm
       5. mRNA must attach to the ribosome correctly to undergo translation

   19. Which of the following DOES occur in post-transcriptional processing of pre-mRNA in eukaryotes?
       1. Addition of poly-A tail at 3' end
       2. Addition of CAA at 3' end
       3. Excision of exons
       4. Joining together of introns
       5. None of the above

   20. Which of the following DOES occur in post-transcriptional processing of pre-mRNA in prokaryotes?
       1. Addition of poly-A tail at 3' end
       2. Addition of CAA at 3' end
       3. Excision of exons
       4. Joining together of introns
       5. None of the above

7. 21. What is/are the main difference(s) between translation in eukaryotes and prokaryotes?
       1. Translation occurs on ER-bound ribosomes in prokaryotes, but not in eukaryotes.
       2. Transcription and translation are coupled in eukaryotes; they proceed separately in prokaryotes.
       3. Most eukaryotic mRNAs appear to be monogenic while those of prokaryotes are polygenic.
       4. Methionine instead of N-formyl methionine is translated from one of the initiation codons in prokaryotes.
       5. Two of the above.

8. 22. The DNA of phage lambda (a double stranded DNA virus) has 1.2 x 10⁵ nucleotides. How many proteins of molecular weight 40,000 could be coded by this DNA? Assume a molecular weight of 100 for the average amino acid.
       1. 2 x l0⁴
       2. 400
       3. 100
       4. 50
       5. Cannot be determined from the information given.

9. 23. About 1 x 10¹² ribosomes are stored in an amphibian egg in preparation for the extraordinarily high rate of protein synthesis needed to sustain the rapid cell divisions during early embryological development. The rate of ribosome production in the oocyte is increased primarily by an approximately 1 x 10³-fold rRNA gene amplification. These genes are also transcribed in oocytes at nearly maximum rate, whereas, in somatic cells they are transcribed at only a fraction of the maximum rate. Approximately how many years would be required to synthesize 10¹² ribosomes at an average somatic cell rate of 3 x 10⁶ ribosomes per day?
       1. 3.3 x 10⁵
       2. 3 X 10⁶
       3. 1.1 x10⁹
       4. 1 x 10¹²
       5. None of the above

10. 24. Given the following hypothetical partial base sequence on a sense strand of DNA and the hypothetical amino acyl-tRNA complexes, five amino acids which would be linked together as part of a polypeptide during translation would be? DO NOT USE THE ATTACHED COPY OF THE GENETIC CODE TO ANSWER THIS OUESTION.
        3' GTCAGGAGCGTAAAG 5'

        

        1. Phe-Ala-Ileu-Glu-Cys
        2. Ala-Cys-Ileu-Glu-Phe
        3. Glu-Phe-Ala-Ileu-Cys
        4. Glu-Ala-Cys-Ileu-Phe
        5. Cys-Glu-Ileu-Ala-Phe

11. 25. According to one theory, eons ago, photosynthetic bacteria established a symbiotic relationship with the ancestors of plant cells. What organelle is believed to have evolved from these photosynthetic bacteria?
        1. Mitochondria
        2. Chloroplast
        3. Nucleolus
        4. Ribosome
        5. centriole

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Correct Answers for this Test (question # -- answer)

1 -- A	6 -- B	11 -- C	16 -- A	21 -- C
2 -- C	7 -- D	12 -- D	17 -- C	22 -- D
3 -- E	8 -- C	13 -- B	18 -- C	23 -- E
4 -- C	9 -- A	14 -- C	19 -- A	24 -- B
5 -- E	10 -- A	15 -- A	20 -- E	25 -- B

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