Health and disease

• communicable diseases


  Diseases caused by pathogens that can be transmitted from one individual to another
• Pathogens


  Microorganisms that cause diseases
• three factors that affect health

  Diet, stress, life situation
• Four types of pathogens

  viruses, bacteria, parasites, fungi
• How do bacteria make you ill?

  Reproduce rapidly and damage cells + Produce toxins
• How do viruses make you ill?

  Live and reproduce inside cells, causing damage
• How can pathogens be spread?

  Water, air and direct contact
• 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 AIDS be treated?

  Antiretrovial 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 a plant's growth?

  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 we use Agrobacterium tumefaciens in plants?

  They cause galls --> genetic manipulation
• 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.

  Engulf pathogens + Produce antibodies + Produce antitoxins
• What are antibodies?


  Substances created in the body to attack specific foreign substances called antigens.