Selected MCQ

Current Question
Which level of protein structure is most directly stabilized by hydrogen bonds between backbone groups?
  • A. Primary
  • B. Secondary
  • C. Tertiary only
  • D. Quaternary only
Correct Answer: B
Explanation:
(\alpha)-helices and (\beta)-sheets arise from backbone hydrogen bonding patterns.
Related Question 1
Which structure is site of protein synthesis?
  • A. Nucleus
  • B. Ribosome
  • C. Lysosome
  • D. Golgi
Correct Answer: B
Explanation:
Ribosomes assemble amino acids.
Related Question 2
Which enzyme breaks hydrogen bonds in DNA?
  • A. Ligase
  • B. Helicase
  • C. Polymerase
  • D. Primase
Correct Answer: B
Explanation:
Helicase unwinds DNA strands.
Related Question 3
Which process most directly forms soil horizons over long timescales?
  • A. Instantaneous melting
  • B. Weathering combined with organic accumulation and leaching
  • C. Oceanic spreading
  • D. Lunar tidal forcing
Correct Answer: B
Explanation:
Soil profiles develop from parent material alteration plus biological and hydrologic processes.
Related Question 4
Which biomolecule directly stores hereditary information in most organisms?
  • A. Protein
  • B. DNA
  • C. Lipid
  • D. Polysaccharide
Correct Answer: B
Explanation:
DNA encodes genetic information in nucleotide sequence.
Related Question 5
Which reagent most directly distinguishes aldehydes from ketones under mild conditions?
  • A. Bromine water
  • B. Tollens’ reagent
  • C. Dilute HCl
  • D. Sodium chloride
Correct Answer: B
Explanation:
Aldehydes reduce Tollens’ reagent whereas ordinary ketones generally do not.