Parasitism

Question 1

In Good Health, Thank Your Trillion Bacteria:

Answer 1

The trillions of bacteria help to:
Digest food
Synthesize certain vitamins

Question 2

Parasitism Key Concept 1:

Answer 2

Parasites typically feed on only one or a few host species
host species have multiple parasite species
Parasites have to withstand being exposed by their host

Question 3

Microscopic Ectoparasite:

Answer 3

1. Scabies or the itch mite
   Mouthparts & cutting front legs with back legs to anchor into your skin
2. Athlete’s Foot

Question 4

Endoparasites

Answer 4

live inside their hosts eg; Tapeworms (greys anatomy)

Question 5

Scolex

Answer 5

suckers and hooks attach to the intestinal wall

Question 6

Parasitism Key Concept 2:

Answer 6

Hosts have mechanisms for defending themselves against parasites, and parasites have mechanisms for overcoming host defences.
Mosquitoes do not cause malaria
Gametophytes
Merozoites in the feeding stage
The feeding stage is also called the trophozoite
Plasmodium parasite is what causes malaria

Question 7

Parasitism Key Concept 3

Answer 7

Hosts and parasite populations can evolve together, each in response to selection pressure imposed by the other.
Nematoid refers to a worm
Strong selection on parasites from hosts, and hosts have a strong selection on parasites

Question 8

Coevolution

Answer 8

Rabbits are more resistant, and the virus is less lethal
Rabit mortality rate goes down after multiple epidemics
Evolution of building resistance to myxoma virus
Coevolution between the host and parasite

Question 9

Parasitism Key Concept 4

Answer 9

Hosts and parasites can have important effects on each other’s population dynamics
Environment consists of 2 populations:
1. Host population
2. Parasite population
Skin sores from leishmaniasis
Caught in the tropics by a protist
Can be caught sometimes by mosquitoes
More and more cases showing up every year
Environmental context: will determine the relationship between the host and the parasite

Question 10

Parasitism Key Concept 5

Answer 10

Parasites can alter the outcomes of species interactions, thereby causing communities to change.
Parasites can alter the physical environment
Ecosystem engineers: coral reef
With the keystone species removed from the community we see a shift in alternative stable states

Question 11

The Plague

Answer 11

Might have reduced the world population from 475 million to 350-375 million in the 14th century