Paraste adaptations

Question 1

What is the difference between micro and macroparasites?

Answer 1

Micro - protazoa, bacteria, viruses.

Macro - ectoparasites, helminths (1/4 of all families are parasites)

Question 2

What are morphilogical adaptations in relation to penetration?

Answer 2

Hooks, suckes, teeth (leeches)
Needle-like mouthparts (moquito)
Barbed mouth parts (ticks)
TICKS - Dorsoventrally flattened to prevent host removal, common feature of ectoparasites

Question 3

How do parasites avoid being digested?

Answer 3

Nematodes - strong impermeable cuticle
Cestodes have tegument
Helminths stimulate host gut to secrete mucous to surround parasite - protect from digestive juices
Most helminthes produce antienzymes protecting them from gastic juice and digestive enzymes.

Question 4

What is the pH of gastric acid?

Answer 4

1.5-3.5

Question 5

What are the physiological adaptations of parasites?

Answer 5

Reduction of unnecessary structures.
Reduced sense organs, nervous +locomotive system.
High fecundity
Resistant stage - HUMAN HOOKWORM EXHIBITS CRYPTOBIOSIS

Question 6

What is innate immunity?

Answer 6

consists of cells + proteins always ready to mobilize + fight microbes at site of infection
Main components:
epithelial barriers
phagocytic leukocytes
dendritic cells
lymphote cell called NATURAL KILLER
circulating plasma proteins.

Question 7

What is the ADAPTIVE immune system?

Answer 7

called into action against pathogens that overcome INNATE.

normally silent, but when activated, adapts by creating potent mechanisms for neutralizing + eliminating microbes.

Question 8

What are the two types of ADAPTIVE IMMUNE SYSTEM?

Answer 8

Humoral - mediated by antibodies produced by B lympochytes

cell mediated - T lymphocytes

Question 9

What is antigenic variation?

Answer 9

bacterium/virus alters surface proteins to evade host immunity, allows re-infection, antibodies not recognized by hosts immune system