Cell Structure and Organelles MCQs Quiz 29 Posted on April 6, 2026Author agropublishers 0 1. Catalase is a highly efficient antioxidant enzyme found in nearly all aerobic organisms, it detoxifies hydrogen peroxide (H₂O₂) by converting it into _______ Carbon dioxide and water Water and oxygen Water and Carbon dioxide Oxygen and carbon monoxide 2. Which organelle is generally absent in prokaryotic cells _______ Ribosome Nucleus Cytoplasm Cell membrane 3. The cytoplasm of prokaryotes includes _______. DNA Cytosol and suspended molecules Ribosomes Enzymes 4. The DNA of most prokaryotes is typically _______ Linear and single Circular and single Fragmented Linear and multiple 5. The cytosol primarily consists of _______ Lipids only Water, ions, and macromolecules Proteins only DNA and RNA only 6. In the phospholipid bilayer of the plasma membrane, the hydrophilic (polar) heads are oriented ___________ Away from any aqueous environment, facing only each other Toward the hydrophobic fatty-acid tails in the membrane interior Randomly, with no consistent orientation Toward the aqueous environments on both the extracellular and cytoplasmic sides 7. Which statement best describes the role of NADH in cellular ATP production? NADH stores the high-energy phosphate bonds of ATP NADH directly phosphorylates ADP to make ATP NADH donates electrons to Complex I of the electron transport chain NADH inhibits ATP synthase to regulate its activity 8. Transcription is the biological process of _______ from a DNA template Protein synthesis DNA duplication ATP production RNA synthesis 9. The final electron acceptor in aerobic respiration, essential for ATP production, is _______ Oxygen NAD⁺ Carbon dioxide Glucose 10. The cytoplasm in prokaryotes primarily consists of _______. Nuclear matrix Cytosol with suspended components Membrane stacks Organelles Loading … Question 1 of 10
