Question: What are communicable diseases caused by?

Answer: Infective organisms known as pathogens.

Question: What are the types of pathogens?

Answer: Bacteria, viruses, fungi and protoctista.

Question: What is a communicable disease?

Answer: A pathogen that can be passed on from one organism to another.

Question: What is a vector?

Answer: A living or non living factor that transmits a pathogen from one organism to another. e . g . malaria mosquito

Question: What two ways can bacteria be classified?

Answer: - By their

: rod (bacilli), spherical (cocci) , comma (vibrios), spiralled (spirilla), corkscrew (spirochaetes)

• By their

• :

• Gram staining can be used to differentiate them:

• +tve purple blue

• -tve red

• Question: What are antibiotics?

• Answer: The chemical or compound that kills or inhibits the growth of bacteria.

• Question: What are viruses?

• Answer:

• Question: What are bacteriophages?

• Answer: Viruses that attack bacteria.

• Question: How do protocista act as pathogens?

• Answer: Parasitic using people or animals as their host organism.

• They may need a vector to transfer them to their hosts or enter the body directly via polluted water.

• Question: How do fungi act as a pathogen?

• Answer: