2.3 Living process Unicellular organism

• Muscle cell

  • Contracts and relax muscle to generates movements.
• Nerve cell

  • Sending nerve impulses.
• White blood cell

  • Destroying pathogen.
• Red blood cell

  • Optimise transportation of oxygen.
• Epithelial cell

  • Coats the surfaces of organs
• Sperm cell

  • Has a long tail to enable it swim towards the ovum in fallopian tube.
  • Head carries a set of chromosomes from the male.
• Sieve tube element

  • Transport organic materials from leaves to storage organs.
• Xylem vessel

  • Transport water and mineral salts from roots to other parts of the plant.
• Palisade mesophyll cell (contains high chlorophyll density)

  • Allows maximum absorption of sunlight for photosynthesis.
• Spongy mesophyll cell

  • Large air spaces allows exchange of gas from the inside of the leaves to palisade mesophyll cell.
• Guard cell

  • Controls the opening and closing of the stoma.
  • Stoma is the opening that allow gas exchange of oxygen and carbon dioxide.
• Root hair cell

  • Adds surface area of absorption of water and mineral salts.