Invertebrates

Question 1

Invertebrates

Answer 1

first animals to evolve, have no backbone

Question 2

Porifera

Answer 2

sponges, believed to be the first animals to evolve, have no symmetry, tissues or organs

Question 3

Cnidaria

Answer 3

jelly fish and coral builders, have radial symmetry, epithelium, sacklike gut, nerve net and muscle

Question 4

Platyhelminthes

Answer 4

flatworms, tapeworms, simplest organism with bilateral symmetry, have organs, first with cephalization and bilateral nerve cord

Question 5

Nematoda

Answer 5

roundworms, pinworms, heart worms, Loa Loa (african eye worm) first with tube digestive system

Question 6

Mollusca

Answer 6

clams, squids, octopi, first with advanced body cavity

Question 7

Annelida

Answer 7

earthworms, leeches, first with segmentation and closed circulatory system

Question 8

Arthropoda

Answer 8

spiders, insects, crustaceans, greatest number of species of any animal

Question 9

Chordata

Answer 9

sometime during their life cycle they have notochord, nerve cord, pharynx and tail, arose during Cambrian period or just before, includes tunicates and lancelets

Question 10

How long ago did large plants and animals colonize the land?

Answer 10

approximately 500 mya