Intro

Question 1

Define parasite

Answer 1

An organism that is dependent metabolically on another (absolutely needs something to survive and reproduce!), where that organism benefits at the expense of the other.

Question 2

Name 3 major groups of parasite

Answer 2

helminths, protozoa and arthropods

Question 3

How can parasites cause harm

Answer 3

1. the number
2. The site (brain)
3. Feeding habits (liver fluke feed on blood, compromising liver function and anaemia)
4. competition for nutrients

Question 4

Cost of parasites

Answer 4

1. Diseased animal - welfare, productivity

2. Preventing disease - anthelmintic use, managing prophylactic treatments

Question 5

Types of infectious pathogen

Answer 5

1. Virus
2. BActeria
3. Fungi
4. Parasites

Question 6

How do viruses cause disease

Answer 6

• Viruses invade a host and attach themselves to a cell. As they enter the cell, they release genetic material. The genetic material forces the cell to replicate, and the virus multiplies. When the cell dies, it releases new viruses, and these go on to infect new cells.
• Genetic code and protein-fat coat
• e.g. norovirus, herpes simplex, zika, influenza

Question 7

BActeria

Answer 7

• Bacteria are single-celled microorganisms known as prokaryotes
• Unicellular
• E.g. pneumonia, bacterial meningitis, food poisoning

Question 8

Fungi

Answer 8

• A fungus is an often-multi-cellular parasite that can decompose and then absorb organic matter using an enzyme. They almost always reproduce through the spreading of single-celled spores, and the structure of a fungus is normally long and cylindrical with small filaments branching from the main body. This structure is known as hypha.
• E.g. athletes’ foot, ringworm

Question 9

Parasites

Answer 9

• Single-celled eukaryotes e.g. malaria

* Multi-cellular eukaryotes e.g. helminths, ectoparasites

Question 10

Examples of helminths

Answer 10

(worms)
o	Nematodes (roundworms)
o	Platyhelminths (cestodes and flukes)

Question 11

Examples of Arthropods

Answer 11

o Arachnids

o Insects

Question 12

Examples of Protozoa

Answer 12

o Single celled organisms

Question 13

How do you write a parasite name?

Answer 13

1. GENUS followed by SPECIES

2. ALWASY IN ITALICS

Question 14

Helminth, Nematodes general features

Answer 14

1. Round worms
2. If free living = don’t infect host - lot in soil
3. Cylindrical
4. Range of sizes, can be quite large ½ mm to 20-40 cm in size!
5. Both free living and parasitic species ~25,000 nematodes described half of which are parasitic
6. Half of nematodes are parasitic
7. Free = don’t need a host to reproduce

Question 15

Anatomy of nematode

Answer 15

•	Cuticle  protective outer wall
•	Hyperdermis also helps maintain integrity of worm
•	Muscle cells help maintain cylinder 
•	Fluid filled cavity that have structures within:
o	Gut (runs full length of worm)
o	Female  uterus with eggs
•	Nematodes are dioecious 
•	Nervous system also runs full length

Question 16

Nematode digestive system mouth to anus

Answer 16

1, mouth

2. Buccal Cavity
3. Oesophagus
4. Intestine
5. ANus

Question 17

Which parasites do we need to know both genus and species names?

Answer 17

1. Teladorsagia circumcincta
2. Trichostrongylus axei (abomasum)
3. Haemonshun contortus
4. Nematodirus Battus (distinct egg hatching)

Question 18

Which parasites do only need to now GENUS. And what is it followed by?

Answer 18

1. Followed by spp
2. Trichostrongylus spp (SI)
3. Nematodirus spp - know there are other species in addition to battus which don’t have specific egg hatching preference
4. Cooperia spp