Master GCSE Biology

MS1:

- (1 mark) Respiration is the process by which organisms release energy from food.

MS2:

- (1 mark) Photosynthesis is the process by which plants use sunlight to produce glucose and oxygen.

- (1 mark) Glucose is the main energy source for living organisms, while oxygen is used in aerobic respiration.

MS3:

- (1 mark) Aerobic respiration

- (1 mark) Anaerobic respiration

MS4:

- (1 mark) Chlorophyll is a green pigment that absorbs sunlight.

- (1 mark) The absorbed sunlight energy is used to split water molecules into hydrogen and oxygen.

- (1 mark) The hydrogen is then used to convert carbon dioxide into glucose.

MS5:

MS6:

- (1 mark) Limiting factors are factors that limit the rate of photosynthesis.

- (1 mark) Factors such as light intensity, carbon dioxide concentration, and temperature can act as limiting factors.

- (1 mark) When a limiting factor is present, the rate of photosynthesis cannot increase beyond a certain point.

- (1 mark) Light intensity is usually the limiting factor in most natural environments.

MS7:

- (1 mark) Anaerobic respiration does not require the presence of oxygen.

- (1 mark) Anaerobic respiration produces lactic acid instead of carbon dioxide and water as waste products.

MS8:

- (1 mark) Lactic acid

- (1 mark) Ethanol

MS9:

- (1 mark) Oxygen debt refers to the additional oxygen required by the body after strenuous exercise.

- (1 mark) This oxygen is used to repay the debt created during anaerobic respiration during exercise.

- (1 mark) The debt is paid off through aerobic respiration, which produces carbon dioxide and water.

MS10:

- (1 mark) Metabolism refers to the chemical reactions that occur in living organisms.

- (1 mark) Metabolism provides energy for essential life processes, such as cell division, growth, and reproduction.

- (1 mark) Metabolism also helps regulate body temperature and maintain the stability of internal environments (homeostasis).