Infection and response

• What are communicable diseases?

  Diseases caused by pathogens that can be transmitted from one individual to another.
• Define 'pathogens'.

  Microorganisms that cause diseases.
• Define 'health'.

  State of physical and mental well-being.
• Suggest three factors that affect health.

  Diet, stress, life situations (e.g. Hygiene), pathogens, immune system.
• State the four types of pathogens.

  Bacteria, viruses, protists, fungi.
• How do bacteria make you ill?

  Reproduce rapidly and produce toxins that damage cells.
• How do viruses make you ill?

  Produce inside body cells, causing damage.
• How can pathogens be spread?

  By air/droplet infection, direct contact, water.
• State one method to prevent the spread of disease.

  Isolation; maintain good hygiene; Destroy vectors; Vaccination.
• Name a viral disease that leads to blindness and brain damage.

  Measles.
• How can measles spread?

  Droplet infection.
• Name the pathogen that causes AIDS.

  HIV (Human immunodeficiency virus).
• How can HIV be spread?

  Sexual contact; Exchange of bodily fluids (shared needles, blood transfusion).
• How can HIV infection be treated?

  Antiretroviral drugs to control (not cure) it.
• Name a viral disease in plants.

  Tobacco mosaic virus.
• Describe the appearance of a plant infected with tobacco mosaic virus?

  Mosaic pattern of discoloration on leaves.
• How does tobacco mosaic virus affect the plants?

  Destroy chloroplasts, so reduce photosynthesis.
• How can tobacco mosaic virus be spread?

  Direct contact/Vectors.
• Viral diseases can be cured. True or False?

  FALSE.
• Where can salmonella bacteria be found?

  Raw meat, chicken, eggs.
• State one symptom of salmonella poisoning.

  Fever/Abdominal cramps/diarrhoea/vomiting.
• Which pathogen causes gonorrhoea?

  Bacteria.
• How does gonorrhoea spread?

  Sexual contact.
• State a symptom of gonorrhoea.

  Yellow/green discharge from penis/vagina; pain on urination.
• State a long-term effect of gonorrhoea.

  Long-term pelvic pain, infertility, ectopic pregnancies.
• How can the spread of gonorrhoea be stopped?

  Use condom; Limit sexual partners.
• How can bacterial diseases be treated?

  Antibiotics.
• Name a fungal disease in humans.

  Athlete's foot.
• Which pathogen causes rose black spot?

  Fungi.
• State a symptom of rose black spot.

  Damages leaves.
• Which pathogen causes malaria.

  Protists.
• How is malaria spread?

  By female Anopheles mosquitoes.
• How does malaria affect the body?

  Damages blood and liver cells.
• State a symptom of malaria.

  Fevers, shaking.
• How can the spread of malaria be stopped?

  Use mosquito nets; Use insecticides; Remove standing water; Take antimalarial drugs.
• How does your skin act as a defence against pathogen entry?

  Barrier; Antimicrobial secretions; Microorganism layer.
• How does the trachea defend the body against pathogens?

  Secrete mucus to trap pathogens + Cilia move mucus up the trachea to be removed.
• How does the stomach defend the body against pathogens?

  Hydrochloric acid destroys microorganisms in mucus/food.
• State the three ways in which white blood cells defend the body.

  hydrochloric acid destroys microorganisms in mucus/food.
• State the three ways in which white blood cells defend the body.

  Engulf pathogens + Produce antibodies + Produce antitoxins.