Communicable diseases

Question 1

What are viruses?

Answer 1

• Not cells
• Not living
• Still considered an organism
• 10, 000 times smaller than animal cells.

Question 2

How do viruses reproduce?

Answer 2

• Can’t reproduce by themselves.
• If inside another organisms cell, they can use that cells own machinery to reproduce inside the cell until that host cell bursts.

Question 3

State 3 examples of viral disease.

Answer 3

• Measles
• HIV
• Tobacco Mosaic Virus (TMV)

Question 4

Measels:
- How are they spread?
- Symptoms
- Prevention

Answer 4

Spread: By droplets when an infected person coughs or sneezes (airborne).

Symptoms: Red rash across body, Fever

Prevention: Everyone is vaccinated in the UK when they are young.

Question 5

HIV:
- How are they spread?
- Symptoms
- Prevention

Answer 5

Spread: Sexual contact / Exchanging bodily fluids

Symptoms: Flu-like symptoms - fever, tiredness, aches. They will start to fell better but be unaware of the virus damaging their immune system. At this point they can catch unusual infections, sometimes develop cancers. Both of these are AIDS.

Prevention: Antiretroviral (prevent virus from replicating)

Question 6

TMV: (affects plants)
- How are they spread?
- Symptoms
- Prevention

Answer 6

Spread: Direct contact between plants.

Symptons:
- Causes a mosaic pattern on the leaves.
- parts of the leaves become discoloured.
- stunted growth

Prevention: strict hygiene and sanitation practices.

Question 7

Rose Black spot: Fungal diseases
- How are they spread?
- Symptoms
- Prevention

Answer 7

Spread: Through environment in water or by wind.

Symptoms:
-Purple or black spots
- leaves turn yellow and drop off
- stunted growth

Prevention:
- using fungicides
- stripping the plant of infected leaves

Question 8

Malaria: Protist disease
- How are they spread?
- Symptoms
- Prevention

Answer 8

Spread: Mosquito

Symptoms:
- repeating episodes of fever

Prevention:
- stopping mosquitoes from breeding
- spraying any exposed skin with an insect repelent
- sleeping under a mosquito net.

Question 9

Salmonella: bacterial
- How are they spread?
- Symptoms
- Prevention

Answer 9

Spread: Eating foods that have been contaminated with Salmonella bacteria.

Symptoms:
-fever
- stomach cramps
- vomiting and diarrhoea

Prevention:
Most poultry are vaccinated against Salmonella.

Question 10

Gonorrhoea: bacterial
- How are they spread?
- Symptoms
- Prevention

Answer 10

Spread:
- Sexually transmitted disease (STD)
- sexual contact

Symptoms:
- pain when urinating
- thick yellow or green discharge

Prevention:
- originally treated with an antibiotic called penicillin but bacteria became resistant to it.
- use protection
- antibiotics