IB BIO I Replication/Transcription/Translation Van Roekel/Madden. Name Date Period. D. It separates DNA strands. (Total 1 mark)

Transcription

1 Name Date Period 1. What is the function of helicase? A. It forms bonds between DNA nucleotides. B. It adds new nucleotides to the DNA helix. C. It forms the DNA helix. D. It separates DNA strands. 2. Which enzyme removes the RNA primer during replication? A. RNA primase B. DNA polymerase I C. DNA ligase D. Helicase 3. A biochemist isolated and purified molecules needed for DNA replication. When some DNA was added replication occurred, but the DNA molecules formed were defective. Each consisted of a normal DNA strand paired with segments of DNA a few hundred nucleotides long. Which of the following had been left out of the mixture? A. DNA ligase B. Helicase C. Nucleotides D. DNA polymerase 4. Which events take place in DNA replication? I. Formation of messenger RNA II. Unwinding of DNA double helix III. Formation of complementary strands by DNA polymerase A. I and II only B. I and III only C. II and III only D. I, II and III 1

2 5. The diagram below shows the bases on a short section of DNA during replication. Identify the sequence of bases on the new complementary strand labelled I in the diagram. A G A T C I A. CTAG B. CUAG C. TCGA D. AGCT 6. Which substance is a base found in RNA? A. Ribose B. Thymine C. Phosphate D. Uracil 7. How would the following DNA sequence, ACGTTGCATGGCA, be transcribed? A. UGCAACGUACCGU B. TGCAACGTACCGT C. ACGTTGCATGGCA D. ACGUUGCAUGGCA 2

3 8. What enzyme is used in transcription but not in replication? A. DNA polymerase B. Helicase C. Protease D. RNA polymerase 9. What is an intron? A. The 3 5 strand of a DNA double helix B. The 5 3 strand of a DNA double helix C. A section of mrna removed before translation D. A trna with a start anticodon 10. Why are the messenger RNA molecules received by eukaryotic ribosomes shorter than the messenger RNA molecules formed by transcription of DNA? A. Base deletion mutations make the mrna shorter. B. Start codons are not at the end of the mrna molecule. C. Introns are removed before the RNA is translated. D. Bases are removed from the ends of the mrna each time it is translated. 11. Where is an anti-codon located? A. trna B. mrna C. DNA D. Ribosomes 12. During the process of translation which of the following statements describes the relationship between nucleic acids? A. Anticodons on mrna bind to complementary codons on DNA. B. Anticodons on trna bind to complementary codons on mrna. C. Bases on DNA bind to complementary bases on mrna. D. A single strand of mrna is produced from the DNA in the nucleus. 3

4 13. If mrna has a codon CAU, what is the corresponding anticodon on the trna molecule? A. CAT B. GUA C. CAU D. GTA 14. A certain gene in a bacterium codes for a polypeptide that is 120 amino acids long. How many nucleotides are needed in the mrna to code for this polypeptide? A. 30 B. 40 C. 360 D Which stage of translation is illustrated by the diagram below? A. Termination B. Initiation C. Translocation D. Elongation 4

5 16. Which are the correct directions of the following processes? Replication Transcription Translation A. 5 to 3 3 to 5 3 to 5 B. 3 to 5 5 to 3 5 to 3 C. 5 to 3 5 to 3 5 to 3 D. 3 to 5 3 to 5 3 to 5 Short Answer/Essay 17. The following diagram represents replication in DNA. A B (a) (b) (c) State the name and describe the function for the enzymes labelled A and B on the diagram. Identify the cellular location of DNA replication in eukaryotic cells. State at which period during the cell cycle DNA replication occurs. (2) (d) Explain the significance of complementary base pairing during DNA replication. (2) 18. Living organisms use DNA as their genetic material. Explain how DNA is replicated within the cells of living organisms. (Total 8 marks) 19. Describe the genetic code. 20. Explain the process of transcription in eukaryotes. 21. Outline the process of translation. (Total 8 marks) 5