(a) State two roles each of the following compounds in respiration: (i) glucose; (ii) oxygen. (b) List two types of cellular respiration (c) Name the struct...

Answer Details

(a) Roles in respiration

(i) Glucose

• It is the respiratory substrate (fuel) that is broken down (oxidised) to release energy.
• Its breakdown yields ATP (energy), carbon dioxide and water for the cell's activities.

(ii) Oxygen

• It is used to oxidise glucose completely (it is the final acceptor of hydrogen/electrons).
• It makes aerobic respiration possible, releasing the maximum amount of energy and producing carbon dioxide and water.

(b) Two types of cellular respiration: aerobic respiration and anaerobic respiration.

(c) Structures of gaseous exchange

(d) Diagram of an open stoma

Draw the stoma 6 cm to 8 cm long showing two bean-shaped guard cells enclosing the open stomatal pore (aperture), with the following labels: guard cell, chloroplasts (inside the guard cells), nucleus, stomatal pore (opening), thick inner wall and thin outer wall of the guard cell, and the neighbouring epidermal cells.