Which organ produces bile? A. Pancreas B. Liver C. Kidney D. Stomach Explanation: Liver synthesizes bile.
Which process requires oxygen? A. Fermentation B. Glycolysis C. Aerobic respiration D. Photosynthesis Explanation: Oxygen is final electron acceptor.
Which molecule carries genetic code to ribosome? A. tRNA B. mRNA C. rRNA D. DNA Explanation: mRNA transports genetic information.
Which structure contains genetic material in eukaryotes? A. Ribosome B. Nucleus C. Golgi D. Lysosome Explanation: DNA is stored in nucleus.
Which enzyme breaks hydrogen bonds in DNA? A. Ligase B. Helicase C. Polymerase D. Primase Explanation: Helicase unwinds DNA strands.
Which reaction is exothermic? A. Photosynthesis B. Combustion C. Electrolysis D. Sublimation Explanation: Combustion releases heat.
Which compound shows isomerism? A. CH₄ B. C₂H₆ C. C₄H₁₀ D. CO₂ Explanation: Butane has structural isomers.
Which ionization requires most energy? A. First B. Second C. Third D. Fourth Explanation: Successive ionizations require increasingly more energy.
Which element has smallest atomic radius? A. Li B. Be C. B D. F Explanation: Atomic radius decreases across period; fluorine is smallest.
Which compound has strongest intermolecular forces? A. CH₄ B. NH₃ C. H₂O D. CO₂ Explanation: Water forms extensive hydrogen bonding network.