Phylum Nematoda

Question 1

Ecdysozoa shared characteristics (2)

Answer 1

Periodically moult exoskeleton (cuticle)

No motile cilia or flagella

Question 2

Nematode Body Plan (7)

Answer 2

Multilayered, collagenous cuticle (4 molts)
Longitudinal muscles only
Pseudocoel (hemocoel)
Syncytial epidermis
Anterior nerve ring and longitudinal cords
Absence of motile cilia/flagella
Eutely

Question 3

Nematode Locomotion (3)

Answer 3

Stiff cuticle – multiple layers of collagen fibres having different fibre orientations (store strain energy)
Fluid with pseudocoel maintained under high pressure
Longitudinal muscles only

Question 4

Nematode Reproduction

Answer 4

Asexual: very few species, must be through parthenogenesis
Sexual: Dioecious (few exceptions), internal fertilization, ameboid sperm and 4 moults to the adult stage (4 juvenile stages)

Question 5

Dauer larva

Answer 5

Facultative diapause
Triggered by environmental cues: temp, food density
Age arrest (reduced metabolic rate)
This resistant stage moves from larva 2 to larva 4

Question 6

Hookworm

Answer 6

Intestinal parasite, one host, cuticle around mouth form teeth like projection, consume blood from intestinal wounds, anemia
Adult worms in intestine, 3rd larva infect the skin of human

Question 7

Wuchereria bancrofti

Answer 7

Cause of Elephantiasis
Larva clog lymphatic vessels
Grotesque swelling
Two hosts: human and mosquito

Question 8

Golden nematode

Answer 8

Damaging potato parasite

Cysts on roots are dead, swollen bodies of females – filled with eggs