Ch.14-Interactions among organisms: Parasitism

Question 0

Parasite

Answer 0

an organism that lives in or on a host organism and feeds on its tissues or body fluids

• > often a symbiosis
• > Estimated that 50% of species on earth are parasites

Question 1

Symbiosis

Answer 1

a relationship in which two species live in close physiological contact with each other
-> not mutualism

Question 2

Pathogen

Answer 2

a parasite that causes disease

Question 3

Predation/herbivory

Answer 3

• usually short-term
• eat many individuals
• kills quickly
• lower reproductive rate then prey

Question 4

Parasitism

Answer 4

• usually long-term
• eat one/ few individuals
• usually kills more slowly
• higher reproductive rate than host

Question 5

Can recover from parasitism but not from predation

Answer 5

Death Death Death
^ ^ ^
| | |
Birth->Susceptible->Infected->Recovered

Question 6

Macroparasite

Answer 6

Large enough to see with the naked eye

-Ex: worms, trematodes, etc.

Question 7

Microparasites

Answer 7

too small to see with the naked eye

-Ex: bacteria, protozoans,etc.

Question 8

Many types of parasites

Answer 8

-Malaria, tapeworms, athletes foot, potato blight, HIV, Botfly, Giardia, Flu Virus, Round worm, Rabies virus, Head lice, Foot and mouth disease

Question 9

Vector

Answer 9

any agent that carries and transmits a pathogen

-Parasites can require vectors

Question 10

Host defenses from parasites

Answer 10

• change behavior(avoid sick individuals, move to parasite-free location, etc.)
• immune system
• biochemical defense

Question 11

Parasite adaptations

Answer 11

• encapsulation(prevents detection)

- change host behavior, physiology, survival, or reproduction for their benefit

Question 12

Cost of Parasites

Answer 12

Diseases of crops and livestock:
-plant pathogens cost~33 billion/year
-foot and mouth disease cost 3.4 billion/year
Human parasites
-flu cost 300 million/year