Molecular Genetics of Animal mcqs January 8, 2026April 9, 2024 by u930973931_answers 24 min Score: 0 Attempted: 0/24 Subscribe 1. What is the primary function of DNA polymerase in DNA replication? (A) Adds nucleotides to the growing DNA strand (B) Unwinds the DNA double helix (C) Initiates DNA synthesis (D) Seals nicks in the DNA backbone 2. Which enzyme is responsible for unwinding the DNA double helix during DNA replication? (A) DNA polymerase (B) DNA ligase (C) Topoisomerase (D) Helicase 3. What is the function of RNA polymerase in transcription? (A) Adds ribonucleotides to the growing RNA strand (B) Unwinds the DNA double helix (C) Synthesizes a complementary DNA strand (D) Seals nicks in the RNA backbone 4. Which of the following is NOT a type of RNA involved in gene expression? (A) Messenger RNA (mRNA) (B) Ribosomal RNA (rRNA) (C) Regulatory RNA (regRNA) (D) Transfer RNA (tRNA) 5. What is the function of transfer RNA (tRNA) in translation? (A) Unwinds the DNA helix (B) Transcribes mRNA into protein (C) Synthesizes nucleotides (D) Carries amino acids to the ribosome 6. Which of the following represents the central dogma of molecular biology? (A) DNA replication → Transcription → Translation (B) Transcription → DNA replication → Translation (C) Translation → Transcription → DNA replication (D) Translation → DNA replication → Transcription 7. What is the function of the promoter region in gene expression? (A) Determines the binding site for RNA polymerase (B) Signals the end of transcription (C) Initiates DNA replication (D) Directs the attachment of ribosomes 8. Which genetic mutation involves insertion or deletion of nucleotides? (A) Point mutation (B) Silent mutation (C) Frameshift mutation (D) Missense mutation 9. What is the role of transcription factors? (A) Unwind DNA (B) Initiate DNA replication (C) Regulate transcription of specific genes (D) Carry amino acids to ribosomes 10. Which repair mechanism corrects mismatched base pairs? (A) Nucleotide excision repair (B) Mismatch repair (C) Base excision repair (D) Homologous recombination 11. What is the function of DNA ligase in DNA repair? (A) Seals nicks in the DNA backbone (B) Removes damaged nucleotides (C) Unwinds DNA (D) Synthesizes a complementary strand 12. Which mutation changes the amino acid sequence of a protein? (A) Silent mutation (B) Nonsense mutation (C) Frameshift mutation (D) Missense mutation 13. What is the function of RNA interference (RNAi)? (A) Stimulates translation (B) Enhances DNA replication (C) Degrades mRNA (D) Initiates transcription 14. Which enzyme adds a poly(A) tail to mRNA? (A) DNA polymerase (B) Poly(A) polymerase (C) RNA polymerase (D) DNA ligase 15. What is the role of the Shine-Dalgarno sequence? (A) Initiates transcription (B) Signals end of translation (C) Determines ribosome binding site on mRNA (D) Promotes mRNA degradation 16. Which enzyme removes introns from pre-mRNA? (A) RNA polymerase (B) DNA polymerase (C) Spliceosome (D) RNA ligase 17. What is the function of the polyadenylation signal? (A) Initiates transcription (B) Promotes mRNA degradation (C) Determines ribosome binding site (D) Signals end of transcription 18. Which condition is caused by a mutation in a single gene? (A) Down syndrome (B) Cystic fibrosis (C) Huntington's disease (D) Diabetes mellitus 19. What is the function of DNA methylation? (A) Enhances gene expression (B) Repairs damaged DNA (C) Inhibits gene expression (D) Initiates DNA replication 20. Which enzyme synthesizes the RNA primer during DNA replication? (A) DNA polymerase (B) Helicase (C) Primase (D) Ligase 21. What is the role of DNA helicase? (A) Unwinds DNA (B) Adds nucleotides (C) Initiates synthesis (D) Seals nicks 22. Which enzyme seals nicks in DNA during replication? (A) DNA polymerase (B) Helicase (C) DNA ligase (D) Topoisomerase 23. What is the function of RNA polymerase in transcription? (A) Seals RNA nicks (B) Unwinds DNA (C) Synthesizes complementary DNA (D) Adds ribonucleotides to RNA strand 24. Which of the following is NOT a type of RNA in gene expression? (A) mRNA (B) rRNA (C) regRNA (D) tRNA