Porifera, Cnidaria, Ctenophora

Question 1

What are Porifera and describe how water travels through them

Answer 1

Sponges (‘pore bearers’), water currents enters through ostia, leave via osculum at the top

Question 2

Describe the structure of Porifera’s (2)

Answer 2

Jelly-like extracellular matrix, with collagen, and stiffened with spicules.

Choanocytes (‘funnel cell’), flagella draw water in

Question 3

Describe how Porifera reproduce (2)

Answer 3

Hermaphrodites, but not self fertile. Sperm exits osculum

some reproduce asexually by budding

Question 4

List 3 extant species of Porifera

Answer 4

Demospongia

Hexactinella

Calcarea

Question 5

What are Ctenophora and describe 3 properties of their structure

Answer 5

‘Comb Carriers’.

2 cell layers separated by a gelatinous mesogloea

Complete through gut

Have ctenes, cells with plates of cilia that move the animal

Question 6

Name 3 Cnidaria genera

Answer 6

Hydra, Aurelia, Actinia

Question 7

What are the stinging cells present on Cnidaria called?

Answer 7

Cnidocytes

Question 8

What are the 2 life cycle stages of Cnidaria

Answer 8

Medusa and Polyp

Question 9

What happens to a fertilised egg of Cnidaria

Answer 9

Becomes a free swimming, ciliated planula larva, settles at the bottom and becomes a polyp

Question 10

List 4 classes of Cnidaria

Answer 10

Anthozoa - Sea anemones + corals

Hydrozoa - Hydroids

Scyphozoa - jellyfish

Cubozoa - box jellyfish

Question 11

What life cycle stages do Anthozoa have? Medusa/Polyp?

Answer 11

Polyp

Question 12

Porifera, Ctenophora and Cnidaria are all characterised by a particular cell type unique to that phylum, what are they?

Answer 12

Porifera - choanocytes

Ctenophora - Ctenes

Cnidaria - Cnidocytes