Phylum Cnidaria

Question 1

Symmetry;

What type of symmetry does this animal display?

Answer 1

Radial symmetry.

The body can be divided into 2 halves by an plane that goes through the central axis.
(The animal can be cut in half across any diametee and the 2 halves are mirror images.)

‘Sessile’ describing organisms unable to move.

Question 2

Symmetry;

Why is this phylum’s symmetry useful?

Answer 2

These organisms are sessile and can obtain food from the aqueous medium as they can detect stimuli from 360°.

Question 3

Support;

The body is supported by what 2 things?

Answer 3

• The aqueous medium and
• the hydrostatic skeleton formed by the fluid filled enteron.

Question 4

Gut/feeding;

The animal has a ____ with only one opening, surrounded by tentacles. The prey is
caught on ____

Answer 4

‘sac-like gut’.

‘barbs, injected with poison and then pushed into the mouth by the tentacles’.

Question 5

Gut/feeding;

Digestion is ____, with soluble products
absorbed into the cytoplasm.

Answer 5

‘both extracellular in the gut cavity and intracellular’.