Radiata

Question 1

What symmetry do Porifera express?

Answer 1

Asymmetry

Question 2

What is the substance between the cell layers in radiata?

Answer 2

Mesohyl

Question 3

What groups have HOX genes?

Answer 3

Placazoa and Cnidaria

Question 4

Name the 4 cell types of Placozoa

Answer 4

Epithelial
Fibre
Gland
Shinysphere

Question 5

Name the one species in Placozoa

Answer 5

Trichoplax adhaerens

Question 6

Most diverse group?

Answer 6

Porifera

Question 7

What groups show biradial symmetry?

Answer 7

Ctenophora & Cnidaria

Question 8

What are Cnidaria characterised by?

Answer 8

Stinging cells (Cnidocytes)

Question 9

Give 2 reasons as to why we know Porifera did not evolve from choanoflagellates

Answer 9

• Choanoflagellates are monophyletic

- No pure colonial choanoflagellates

Question 10

What groups are Coelenterata?

Answer 10

Cnidaria

Crenophora

Question 11

What is the placula hypothesis?

Answer 11

Animals evolved from 2 laters of protists which became invaginated to form a gut.

Trichoplax could be evidence

Question 12

What disproves the Placula hypothesis?

Answer 12

mtDNA showed Trichoplax is basal with metazoans but mtDNA isnt good for deep phylogencies