Ecdysozoa

Question 1

What trait do Ecdysozoa phyla have in common?

Answer 1

All have a cuticle that is moulted as they grow

Question 2

How many phyla within Ecdysozoa?

Answer 2

8

Question 3

5 main phyla in Ecdysozoa

NOTAN

Answer 3

Nematodes
Nematomorphs
Tardigrades 
Onychophora
Arthropoda

Question 4

How do nematodes move?

Answer 4

By contrast to worms within the lophotrochozoa superphylum which have both circular and longitudinal muscles which aid locomotion, nematodes only have longitudinal muscles. These contract to create a thrashing motion instead.

Question 5

How do nematodes get their stiffness?

Answer 5

High pressure body cavity (this is why they are roundworms)

Question 6

Well known characteristic of nematodes

Answer 6

Triradiate pharynx

Question 7

Nematode cuticle

Answer 7

Composed of helical collagen fibres

Acts as a flexible and tough exoskeleton

Question 8

What is nematode exoskeleton made of?

Answer 8

Cuticle

Question 9

What is the solution to the combination of a high pressure fluid filled cavity and a through gut?

Answer 9

Presence of muscles to control opening and closing of anus

Muscular (triradiate) pharynx at the mouth