O-Level Pure Biology Paper 1 practice set

O-Level Pure Biology Paper 1 practice set. SET 1 1. Which organelle is the site of aerobic respiration in a cell? A. Ribosome B. Mitochondrion C. Golgi body D. Nucleus 2. Which structure is found in plant cells but NOT in animal cells? A. Cell membrane B. Mitochondria C. Cell wall D. Nucleus 3. Diffusion is best described as the movement of particles: A. From low to high concentration, requiring energy B. From high to low concentration, not requiring energy C. Of water only, across a partially permeable membrane D. Against a concentration gradient using a carrier protein 4. Osmosis is defined as the movement of: A. Solute molecules across a partially permeable membrane B. Water molecules from a region of lower to higher water potential C. Water molecules from a region of higher to lower water potential across a partially permeable membrane D. Any molecule using ATP energy 5. An enzyme's activity is most affected by changes in temperature and pH because these factors: A. Change the substrate's chemical formula B. Alter the shape of the enzyme's active site C. Increase the number of enzyme molecules D. Convert the enzyme into a substrate 6. Which test detects starch? A. Iodine B. Benedict's C. Biuret D. Ethanol emulsion 7. Which test detects protein? A. Iodine B. Benedict's C. Biuret D. Ethanol emulsion

8. Photosynthesis combines which raw materials to form glucose? A. Oxygen and water B. Carbon dioxide and water C. Oxygen and carbon dioxide D. Nitrogen and water 9. Which leaf structure allows gas exchange? A. Cuticle B. Stomata C. Xylem D. Palisade mesophyll 10. Which vessel transports manufactured food from leaves to other plant parts? A. Xylem B. Phloem C. Cambium D. Cortex 11. Which enzyme in saliva begins starch digestion? A. Pepsin B. Amylase C. Lipase D. Trypsin 12. Where is bile released into? A. Stomach B. Duodenum C. Oesophagus D. Large intestine 13. Villi increase absorption efficiency mainly by: A. Producing more enzymes B. Increasing surface area C. Slowing food movement D. Secreting HCl 14. Main function of red blood cells: A. Fight pathogens B. Clot blood C. Transport oxygen D. Transport digested food 15. Which heart chamber pumps oxygenated blood to the whole body? A. Right atrium B. Right ventricle C. Left atrium D. Left ven