35) Unit 2 - The Parasite Niche, Transmission and Virulence

Question 1

What does a parasite do to the host

Answer 1

The parasite forms a symbiotic relationship with the host and benefits from the host by using its nutrients at the expense of the host

Question 2

Is the reproductive potential of the parasite greater or lesser than the host

Answer 2

greater

Question 3

What is an ecological niche

Answer 3

A multidimensional summary of tolerances and requirements of a species

Question 4

what kind of niche do parasites tend to have and why

Answer 4

They tend to have very narrow niches due to high host specificity

Question 5

Parasites are said to be degenerate.

why

Answer 5

Because the host provides so many of the parasites needs they become degenerate because they lack in certain structures and organs

Question 6

name and describe the two types of parasites

Answer 6

ectoparasites - lives on the surface of host

endoparasites - lives within the host

Question 7

Name and describe the two types of hosts

Answer 7

Definitive/Primary:
where the parasite reaches sexual maturity

Intermediate/Secondary:
may be required in order for it to complete its life cycle

Question 8

What is the role of a vector

Answer 8

transmission of parasites

Question 9

Name and describe the two types of niches

Answer 9

•Fundamental (theoretical):
the niche an organism occupies when there is no interspecific competition

•Realised (reality):
The niche an organism occupies in response to interspecific competition

Question 10

what is competitive exclusion principle

Answer 10

when interspecific competition occurs between species with very similar niches, usually one of the two species become extinct

Question 11

what is resource partitioning

Answer 11

when the realized niches are sufficiently different, competing species can co-exist by resource partitioning

Question 12

what is meant by the term transmission and the term virulence

Answer 12

• Transmission - he spread of a parasite to a host

* Virulence - The deleterious effect that the parasite has on a host

Question 13

What factors increase transmission of a parasite

Answer 13

• Overcrowding of host

* a means of transmission such as vectors or water

Question 14

when the hosts behaviour is modified by the parasite this is known as the…

Answer 14

Extended phenotype of the parasite

Question 15

list 3 examples of host behaviour that could be modified

Answer 15

• movement
• Sexual behavior
• Habitat choice

Question 16

why would a parasite modify the hosts behaviour

Answer 16

to maximize transmission

Question 17

what strategies do parasites use benefit their own reproduction or transmission

Answer 17

• suppress host immune response
• modify host size
• modify reproduction rate

Question 18

The distribution of a parasite on a host is uniform.

TRUE OR FALSE?

Answer 18

FALSE.

it is not uniform

Question 19

what allows for rapid evolution and increase in the parasite’s population

Answer 19

Both sexual and asexual phases