Parasite

• Pork tapeworm


  • Suckers and hooks to attach to gut wall
  • Thin and large surface area to volume ratio to maximise absorption of digested food
  • Produces enzyme inhibitors to prevent digestion by host's enzymes
  • Thick cuticle to protect it from host's immune responses
  • Has male and female reproductive structures to allow for sexual reproduction without second tapeworm
  • Produces vast numbers of eggs to increase chances of finding another host
  • Eggs have resistant shells to survive until eaten by secondary host
• The tapeworm does not have a digestive system, so absorbs the products of the host's digestion directly through its cuticle
• Head louse (Pediculus)


  • Legs adapted to be claw-like to grip onto the hairs
  • Lays eggs that are glued to the base of hairs
• Life cycle of head louse

  1. Egg hatches into nymph in 2 weeks

  2. Nymph feeds on blood

  3. Nymph develops into adult in 10 days

  4. Adult lays eggs

  5. Cycle continues
• The head louse is an ectoparasite, which feeds by sucking blood from the scalp of the host
• The head louse is a wingless insect and so can only pass to a new host via direct contact