Invertebrates (Ecdysozoans) (E1)

Question 1

Ecdysozoan

Answer 1

animals shed a cuticle as they grow (molting)

Question 2

Nematodes (Roundworms)

Answer 2

• pseudocoelomate, separate sexes, round body shape, parasites
• Grow by molting (sheds cuticle), decompose and recycles nutrients

Question 3

Arthropods

Answer 3

• segmented body, jointed appendages, exoskeleton, open circulatory system
• Uses hemolymph instead of blood
• The respiratory system made of the trachea and book lungs
• Grow by molting (sheds exoskeleton)

Question 4

Chelicerates

Answer 4

arachnids (spiders, scorpions, ticks) have chelicerae (pincers or fangs) to eat

Question 5

Myriapods

Answer 5

millipedes, centipedes

Question 6

Pancrustaceans

Answer 6

clade formed of crustaceans and insects, head, thorax, post-genital region

Question 7

Insects

Answer 7

open circulatory system, radiates in response to new food sources

Question 8

Incomplete metamorphosis

Answer 8

nymph > adult, competition between each other (grasshopper)

Question 9

Complete metamorphosis

Answer 9

larval > pupal > adult, no competition (butterfly)

Question 10

Echinoderms

Answer 10

coelomates, water vascular system, bilateral symmetry

Question 11

Water Vascular System

Answer 11

1) Water flows in/out madreporite into/out of the water vascular system
2) The foot contains ampulla, when squeezed, water is forced into podium, which expands
3) Relaxing chemicals can let water out the podium, unsqueeze the ampulla, and out the madreporite

Question 12

Asteroidea

Answer 12

starfish, have bilateral symmetry (as larvae)

Question 13

Ophiuroidea

Answer 13

brittle stars

Question 14

Echinoidea

Answer 14

sea urchins

Question 15

Crinoidea

Answer 15

sea lilies, feather stars

Question 16

Holothuroidea

Answer 16

sea cucumbers

Question 17

Chordata

Answer 17

bilaterally symmetrical, coelomates, segmented bodies