biology - 5c - transmission and viruslence

Question 1

What is transmission?

Answer 1

The spread of a parasite to a host.

Question 2

What is virulence?

Answer 2

The harm caused to a host species by a parasite.

Question 3

What are ectoparasites generally transmitted through?

Answer 3

Direct contact.

Question 4

What are endoparasites of the body tissues often transmitted by?

Answer 4

Vectors or by consumption of intermediate hosts.

Question 5

What are factors that increase transmission rates?

Answer 5

 the overcrowding of hosts when they are at high density
 mechanisms, such as vectors and waterborne dispersal stages, that allow the parasite to spread even if infected hosts are incapacitated

Question 6

How is host behaviour often exploited and modified?

Answer 6

By parasites to maximise transmission.

Question 7

What is some host behaviour?

Answer 7

Alteration of host foraging, movement, sexual behaviour, habitat choice or anti-predator behaviour.

Question 8

What does the host behaviour become?

Answer 8

Part of the extended phenotype of the parasite.

Question 9

What ways do parasites often suppress the host immune system and modify host size and reproductive rate?

Answer 9

In ways that benefit the parasite growth, reproduction or transmission.