A2.2.8

• Plastids: a family of organelles with two outer membranes and internal membrane sacs.

  Animals: None

  Fungi: None

  Plants: plastids of varied types f.e. Chloropasts or amyloplasts
• Cell wall: a rigid layer outside the plasma membrane to strengthen and protect the cell

  Animals: none

  Fungi: have walls composed of chitin

  Plants: have walls composed of cellulose
• Vacuole: a flexible fluid-filled compartment surrounded by a single membrane

  Animals: Small temporary vacuoles expel excess water or digest food or pathogens taken in by endocytosis

  Fungi & Plants: there is often a large permanent vacuole used for storage of substances and pressurising the cell
• Centrioles: cylindrical organelles that organise the assembly of structures composed of microtubules

  Animals: used to construct the spindle that moves chromosomes in mitosis and the microtubules in cilia and flagella

  Fungi & Plants: absent, except when there are swimming male gametes, which have a centriole at the base of the flagellum
• Undulipodia: cilia and flagella used to generate movement of a cell or movement of fluid adjacent to a cell

  Animals: cilia and flagella are present in many animal cell, including the tail of male gametes (sperm)

  Fungi & Plants: absent except when there is male gametes that swim using flagella (tails)