BIO 400 Exam 1 Questions and
Answers 100% PASS
What distinguishes a nucleotide from a nucleoside? - CORRECT ANSWER-
Nucleotide = nitrogenous base + sugar + phosphate group; Nucleoside = base +
sugar, no phosphate.
What is the template strand in transcription? - CORRECT ANSWER-The
antisense strand read by RNA polymerase 3′→5′ to synthesize RNA 5′→3′.
What is the coding strand? - CORRECT ANSWER-It has the same sequence as
the RNA transcript (except U replaces T).
Which RNA carries genetic information for protein synthesis? - CORRECT
ANSWER-mRNA.
What are the main types of RNA and their functions? - CORRECT ANSWER-
mRNA = coding info, rRNA = ribosome structure/catalysis, tRNA = amino acid
transfer, snRNA = splicing, miRNA/siRNA = regulation, lncRNA = epigenetic
regulation.
Which base pairs are strongest in DNA? - CORRECT ANSWER-G≡C (3
hydrogen bonds, more stable).
, What stabilizes DNA besides H-bonds? - CORRECT ANSWER-Base stacking via
van der Waals interactions.
What are the major and minor grooves in DNA? - CORRECT ANSWER-Sites
where proteins (e.g., transcription factors) interact with DNA.
Which enzyme unwinds DNA? - CORRECT ANSWER-Helicase.
Which enzyme synthesizes DNA? - CORRECT ANSWER-DNA polymerase.
What is the direction of DNA synthesis? - CORRECT ANSWER-5′→3′, adding
nucleotides to the 3′-OH end.
What are Okazaki fragments? - CORRECT ANSWER-Short DNA synthesized on
the lagging strand.
What enzyme seals nicks between Okazaki fragments? - CORRECT ANSWER-
DNA ligase.
How does DNA polymerase proofread? - CORRECT ANSWER-3′→5′
exonuclease activity.
Which factor binds the TATA box in eukaryotes? - CORRECT ANSWER-TFIID.
What is the Shine-Dalgarno sequence? - CORRECT ANSWER-Prokaryotic
ribosome-binding site upstream of start codon.
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Answers 100% PASS
What distinguishes a nucleotide from a nucleoside? - CORRECT ANSWER-
Nucleotide = nitrogenous base + sugar + phosphate group; Nucleoside = base +
sugar, no phosphate.
What is the template strand in transcription? - CORRECT ANSWER-The
antisense strand read by RNA polymerase 3′→5′ to synthesize RNA 5′→3′.
What is the coding strand? - CORRECT ANSWER-It has the same sequence as
the RNA transcript (except U replaces T).
Which RNA carries genetic information for protein synthesis? - CORRECT
ANSWER-mRNA.
What are the main types of RNA and their functions? - CORRECT ANSWER-
mRNA = coding info, rRNA = ribosome structure/catalysis, tRNA = amino acid
transfer, snRNA = splicing, miRNA/siRNA = regulation, lncRNA = epigenetic
regulation.
Which base pairs are strongest in DNA? - CORRECT ANSWER-G≡C (3
hydrogen bonds, more stable).
, What stabilizes DNA besides H-bonds? - CORRECT ANSWER-Base stacking via
van der Waals interactions.
What are the major and minor grooves in DNA? - CORRECT ANSWER-Sites
where proteins (e.g., transcription factors) interact with DNA.
Which enzyme unwinds DNA? - CORRECT ANSWER-Helicase.
Which enzyme synthesizes DNA? - CORRECT ANSWER-DNA polymerase.
What is the direction of DNA synthesis? - CORRECT ANSWER-5′→3′, adding
nucleotides to the 3′-OH end.
What are Okazaki fragments? - CORRECT ANSWER-Short DNA synthesized on
the lagging strand.
What enzyme seals nicks between Okazaki fragments? - CORRECT ANSWER-
DNA ligase.
How does DNA polymerase proofread? - CORRECT ANSWER-3′→5′
exonuclease activity.
Which factor binds the TATA box in eukaryotes? - CORRECT ANSWER-TFIID.
What is the Shine-Dalgarno sequence? - CORRECT ANSWER-Prokaryotic
ribosome-binding site upstream of start codon.
COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED
