Further up the food chain

B7 OCR GCSE

HideShow resource information
  • Created by: Hayley
  • Created on: 11-06-12 13:03

How are parasites transferred?

- by food or water

- through nose mouth, ****, urinary or genital tracts

- by insect bites

- by burrowing under skin

1 of 4

How do parasites cause damage?

- They feed on nutrients in the gut causing malnutrition and illness

- limit human food supplies

- block water and mineral uptake in crops, causing stunted growth and reducing yields

2 of 4

Malaria parasite's life cycle

1. mosquito injects saliva with parasites

2. Parasite enters liver cell

3.Invades red blood cell

4. repoduces

5. A few parasite cells become sex cells

6. Mosquito sucks up blood with sex cells

7. Fertilization

8. Zygote burrows through mosquito gut wall

9. Reproduces and migrates to salivary glands

3 of 4

Symptoms of sickle cell anaemia

- extreme tiredness

- Short of breath

- blocks blood vessels (don't bend)

- sickle shaped red blood cells

- joint pains

- damages tissues and organs (behind blackage deprived of oxygen)

- damages red blood cells

-not replaced fast enough = anaemia

4 of 4

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »