. A nucleotide is.
Bio 241 Quiz #3 March 22, 2018
Print First and Last Name _______________________________________
I. Multiple Choice: Read each question carefully and select the one best answer for each
question. Write your answer using CAPITAL LETTERS on the line in front of each question.
Questions will be counted wrong if the answer is not written on the line. (1 point each)
_____1. Which of the following is incorrect? A. RNA polymerase – makes a molecule of RNA from an RNA template B. DNA polymerase – makes a molecule of DNA from a DNA template C. DNA ligase – joins segments of DNA D. DNA gyrase (topoisomerase) – releases overwinding strain and untwists DNA E. All of the above are correct.
_____2. A nucleotide is A. a five-carbon sugar, a phosphate group and a nitrogen-containing base B. a sugar with an attached base containing nitrogen C. a six-carbon sugar, a phosphate group and a nitrogen-containing base D. a nitrogen-containing base with an attached five-carbon sugar E. A is correct for DNA and C is correct for RNA
_____3. In DNA synthesis, the primer is synthesized by A. RNA polymerase B. DNA polymerase I C. DNA polymerase III D. Helicase E. DNA gyrase
_____4. Which molecule remains in the nucleus during translation for eukaryotes? A. tRNA B. mRNA C. rRNA D. DNA E. None of the above answers are correct
_____5. What is the effect of a missense mutation in a gene? A. It has no effect on the amino acid sequence of the encoded protein. B. It introduces a premature stop codon into the mRNA. C. It alters the reading frame of the mRNA. D. It prevents introns from being excised. E. It changes an amino acid in the encoded protein.
_____6. Because the synthesis of DNA consists of ½ original DNA and ½ new DNA, DNA replication is said to be
A. discontinuous B. antiparallel C. semiconservative D. complimentary
_____7. In DNA synthesis, the enzyme that erases the primer and fills the gaps with DNA is called
A. DNA ligase B. DNA polymerase I C. DNA polymerase III D. Helicase E. DNA gyrase
_____8. The enzyme responsible for synthesis of leading and lagging strands is A. DNA polymerase I B. DNA polymerase III C. RNA polymerase D. Helicase
_____9. In transcription, as the ribosome translocates along an mRNA molecule by one codon, which of the following occurs?
A. The tRNA that was in the A site moves into the P site. B. The tRNA that was in the P site moves into the A site. C. The tRNA that was in the A site moves to the E site and is released. D. The tRNA that was in the A site departs from the ribosome via a tunnel.
_____10. The genetic code used during translation is based on a 3-nucleotide sequence found on the
A. anti-codon region of tRNA molecules B. codons of mRNA molecules C. codons of rRNA D. RNA promoter E. coding strand of DNA
_____11. What signal causes translation to end? A. a promoter B. RNA polymerase C. An AUG codon D. a termination sequence E. a stop codon
_____12. The pentose in RNA differs from DNA because RNA has A. a hydroxyl (OH) group attached to the number 3’ carbon. B. a hydroxyl (OH) group attached to the number 2’ carbon. C. a hydrogen (H) group attached to the number 3’ carbon. D. a hydrogen (H) group attached to the number 2’ carbon. E. Both B and C are true
_____13. The 3′ end of RNA A. refers to the end that has a hydroxyl group attached to the number 3 carbon on ribose. B. forms a phosphodiester bond with the 5′ phosphate group of the incoming nucleotide. C. refers to the end that has a hydroxyl group attached to the number 2 carbon on ribose. D. Both A and B are true E. Both B and C are true
_____14. At the beginning of transcription, the enzyme responsible for transcription binds to a site on the DNA (in front of the gene) called the
A. Intron B. Exon C. Promoter D. AUG start site E. Codon
_____15. Which strand of the DNA molecule below is the template strand for Promoter 1? A. Red (top) strand B. Blue (bottom) strand C. Both strands can serve as the template strand D. Not enough information to determine
II. Fill in the blank. Label the DNA replication fork. (1 point each)
1. In the above diagram of a DNA replication fork, which letter represents the leading
2. In the above diagram, which letter represents the lagging strand?
3. In the above diagram, which letter represents a 5’ end?
4. In the above diagram, which letter represents a 3’ end?
5. In the above diagram, which letter represents where ligase would work?
If you felt overwhelmed by this quiz, make sure that you attend the BIOL241
SI sessions and utilize your instructor’s office hours!