Parasites

Question 1

What is a parasite?

Answer 1

An organism that takes metabolic advantage of another organism

Question 2

What are zoonoses?

Answer 2

Human infections acquired from animals, caused by agents that infect non human animals

Question 3

Name 9 single celled eukaryotic protozoan parasites of medical importance

Answer 3

1. Plasmodium
2. Toxoplasma
3. Entamoeba
4. Giardia
5. Cryptosparidium
6. Leishmania
7. Trypanosoma
8. Trichomonas
9. Cyclospora

Question 4

What are 2 strategies used to overcome the fragile membrane problem protozoans face?

Answer 4

1. Be transported by arthropod vectors eg. Plasmodium by mosquitoes, leishmania by sandflies and trypanosomes by tsetse flies
2. Alteration between two distinct forms:
   A trophozoite grows within the host
   A dormant non replicating cyst form

Question 5

Give the classifications and an example of each

Answer 5

1. Amoebas eg. Entamoeba histolytica
2. Flagellates eg. Giardia
3. Ciliates. Only 1 is a human parasite, Balantidium coli
4. Apicomplexans eg. Plasmodium

Question 6

Discuss helminths(worms)

Answer 6

They are multicellular animals or metazoa, they reproduce sexually and some are hermaphroditic. They can be divided into roundworms and flatworms

Question 7

What are roundworms? Give an example

Answer 7

They are non segmented or nematodes eg. Ascaris lumbricoides

Question 8

What are flatworms divided into? Give an example of each

Answer 8

They can be divided as:

1. Segmented flatworms (Cestodes or tapeworms)
   eg. Taenia saginata
2. Non segmented flatworms (trematodes or flukes)
   eg. Schistosoma

Question 9

Parasite burden is directly related to?

Answer 9

The number of helminths acquired