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