L4 - Specialised Cells

• The structure of different cells helps them to carry out a particular function within the organism. These cells are called specialised cells.
• Differentiation is the process by which a cell changes to become specialised for a specific job
• The function of Sperm cells are to fertilise an egg.
• Label the parts of a sperm cell:

  A) Tail

  B) mitochondria

  C) Acrosome

  D) nucleus

  
• How are sperm cells adapted for its function?

  Large number of mitochondria in the mid section to release energy for movement.

  Streamlined with a long tail to swim to the egg

  Acrosome containing enzymes to penetrate into the egg
• The function of Nerve cells are to carry electrical signals
• Label the parts of a nerve cell:

  A) Axon

  B) Dendrite

  
• How are nerve cells adapted for its function?

  Long to carry signals long distances.

  Branched connections to connect to other nerve cells and form a network around the body.
• The function of a muscle cell is to contract to enable movement.
• Muscle cells contain a large number of mitochondria to release energy from respiration for movement.
• The function of a root hair cell is to absorb water and minerals from the soil.

  
• How are root hair cells adapted for its function?

  Hair like projections to increase the surface area.

  (Note that root hair cells have no chloroplasts this is because they do not need them as they are in the soil)
• The function of Xylem cells in plants is to carry water and minerals from the roots to the leaves.

  
• How are Xylem cells adapted for its function?

  Form hollow xylem tubes made of dead tissue.

  Long cells with walls toughened by lignin.

  Water and minerals flow from the roots towards the leaves only in one direction
• The function of Phloem cells in plants are to carry glucose around the plant.

  
• How are Phloem cells adapted for its function?

  Form phloem tubes made of living tissue.

  Cells have end plates with holes in them. (sieve plates)

  Glucose in solution moves from the leaves to growth and storage tissues.