Pathogens and disease

Question 1

What are pathogens?

Answer 1

Microorganisms which cause infectious (communicable) disease

Question 2

What can pathogens infect?

Answer 2

• Animals
• Plants

Question 3

How can pathogens be spread?

Answer 3

• Direct contact
• Water
• Air
• Vectors (organisms that carry and pass on the pathogen without getting the disease)

Question 4

How can the spread of infections diseases be reduced?

Answer 4

• Simple hygiene measures. e.g. washing hands, sneezing into a tissue
• Destroying vectors
• Isolating infected individuals (so the pathogen cannot be passed on)
• Giving people are rik a vaccination

Question 5

Viral diseases: How are the caused?

Answer 5

• Viruses rapidly reproduce in body cells, causing damage to the cells.

Question 6

Examples of diseases caused by a virus:
(How they are spread, symptoms and prevention/treatments):

Answer 6

Measles: (animals)
- How it is spread: through AIRBORNE DROPLETS (sneezing and coughing)
- Symptoms: FEVER, RED SKIN RASH, CAN BE FATAL
- Prevention/treatments: Vaccination of children

HIV: (animals)
- How it is spread: through SEXUAL CONTACT, the EXCHANGING OF BODY FLUIDS (e.g. blood)
- Symptoms: FLU-LIKE (initially), A DAMAGED IMMUNE SYSTEM (at this point, body cannot fight off infection/cancers) (late stage infection/AIDS)
- Prevention/treatments: CONDOMS, AVOID SHARING NEEDLES, ANTIRETROVIRAL DRUGS

Tobacco mosaic virus (TMV): (plants)
- Symptoms: MOSAIC PATTERN ON LEAVES which reduces the grown of PHOTOSYNTHESIS

Question 7

Bacterial diseases: How are they caused?

Answer 7

• Bacteria may damage cells directly or produce toxins (poisons) that damage tissues

Question 8

Examples of diseases caused by a bacteria:
(How they are spread, symptoms and prevention/treatments):

Answer 8

Salmonella: (animals)
- How is it spread: through eating CONTAMINATED FOOD
- Symptoms: FEVER, STOMACH CRAMPS, VOMITING, DIARRHOEA
- Preventions/treatments: VACCINATION OF POULTRY, HYGIENIC FOOD PREPARATION

Gonorrhoea: (animals)
- How it is spread: SEXUAL CONTACT
- Symptoms: PAIN WHEN URINATION, YELLOW/GREEN DISCHARGE FROM VAGINA/PENIS
- Preventions/treatments - CONDOMS, ANTIBOTICS

Question 9

Protists and Disease: How are they caused?

Answer 9

• Protists may damage cells directly or produce toxins (poisons) that damage tissues
• Protists are singled celled organisms
• Unlike bacteria, they are eukaryotic

Question 10

Examples of diseases caused by a protists:
(How they are spread, symptoms and prevention/treatments):

Answer 10

Malaria: (animals)
- How it is spread: MOSQUITO VECTORS
- Symptoms: FEVER, CAN BE FATAL
- Prevention/treatment: MOSQUITO NETS, STOP MOSQUITOS FROM BREEDING

Question 11

Examples of diseases caused by a fungus:
(How they are spread, symptoms and prevention/treatments):

Answer 11

Rose black spot: (plants)
- How it is spread: SPORES are carried from plant to plant by WATER or WIND
- Symptoms: PURPLE/BLACK SPOTS on leaves which often TURN YELLOW and DROP OFF EARLY, LOSS OF LEAVES STUNTS the GROWTH of the plant as PHOTOSYNTHESIS IS REDUCE
- Prevention/treatments: REMOVE AND DESTROY INFECTED LEAVES, FUNGICIDES