Expert Physics Tutoring

MS1 (2 marks)

- Photosynthesis is the process in which plants use sunlight to convert carbon dioxide and water into glucose (1)

MS2 (3 marks)

- Chlorophyll absorbs light energy from the sun (1)

- Energy absorbed is used to split water molecules (1)

- Provides electrons for the chemical reactions of photosynthesis (1)

MS3 (4 marks)

- Oxygen is the final electron acceptor in aerobic respiration (1)

- Combines with electrons and hydrogen ions to form water (1)

- Provides energy for the production of ATP (1)

- Without oxygen, aerobic respiration cannot occur (1)

MS4 (2 marks)

- Lactic acid (1)

- or Ethanol (1)

MS5 (3 marks)

- In the absence of oxygen, glucose is broken down to produce lactic acid (1)

- Lactic acid is a waste product that accumulates (1)

- Examples: Bacteria, yeast (1)

MS6 (4 marks)

- Oxygen debt is the extra oxygen required to restore the body to its resting state after strenuous exercise (1)

- During anaerobic respiration, some lactic acid is formed (1)

- Lactic acid is converted back to glucose after exercise, using oxygen (1)

- This process uses up the extra oxygen required (1)

MS7 (2 marks)

- A limiting factor is a factor that affects the rate of photosynthesis beyond which no further increase is possible (1)

- Examples: Carbon dioxide concentration, light intensity, temperature, water availability (1)

MS8 (3 marks)

- Measuring the rate of oxygen consumption (1)

- Using a respirometer or a gas syringe (1)

- Can vary with factors such as temperature, activity, and food intake (1)

MS9 (4 marks)

- Autotrophs make their own food by photosynthesis (1)

- Example: Plants (1)

- Heterotrophs obtain their food from other organisms (1)

- Example: Animals (1)

MS10 (2 marks)

- C₆H₁₂O₆ (1)

- or CH₂OH(CHOH)₄CHO (1)