Kingdoms- Animals

Question 1

5groups in the animal kingdom

Answer 1

Cnidaria
Platyhelminthes 
Annelida 
Arthropoda
Chordata

Question 2

Examples of the phylum Cnidaria

5.8.1

Answer 2

(Marine) Jelly fish and (fresh water) hydra

Question 3

Body form of phylum Cnidaria (and how it is supported)

5.8.1

Answer 3

All forms are multicellular and radially symmetrical
The body is supported by the aqueous medium and there is also a hydrostatic skeleton formed by the fluid filled enteron (gut cavity)

Question 4

Brady wall of Cnidaria

Answer 4

Body wall is composed of two layers of cells surrounding the gut cavity or enteron
Inner is the endoderm and the outer is the ectoderm
In between is jelly

Question 5

Why are they restricted to an aqueous medium

Answer 5

They have no means of restricting water loss across their body surface

Question 6

Phylum Platyhelminths examples

5.8.2

Answer 6

Planarian and liver fluke

Most Platyhelminthes are aquatic free-living flatworms (planarian) but some are highly adapted parasites (liver fluke)

Question 7

Body form of the phylum Platyhelminths

5.8.2

Answer 7

All forms are bilaterally symmetrical and flattened dorso-ventrally

Single opening to the gut -mouth- (the remains of food are passed out through the same body opening through which it enters)
No specialised skeletal system but supported by body tissue

Question 8

Advantage of bilateral symmetry

Platyhelminthes

Answer 8

Animals have a front where sensory receptors can be positioned allowing them to test the environment into which they are entering
(Eye spots symmetrically arranged on the left and right side of the body) evidence of bilateral symmetry

Question 9

Advantage of streamlined bilateral symmetrical shape over radial symmetry of the cnidarians?
Platyhelminthes

Answer 9

Makes movement much easier

Question 10

They have much more tissue than cnidarians

Answer 10

They have a tube like gut rather than a gut cavity (enteron)
Therefore solid tissue fills the space between the outer surface and the gut

Question 11

Ad and disadvantages of solid tissue fills the space between the outer surface and the gut

Answer 11

Allows for specialisation to take place (these are the earliest animals to have developed organs and organ systems)
,many cells per unit volume involved in metabolic activity therefore high demands for oxygen and other metabolites

Question 12

2 major advantages of the for so-ventral flattening of flat worms

Answer 12

Increases the uptake of oxygen (due to high SA:V ratio)

It decreases the diffusion distance from the body surface to body cells

Question 13

Support for Platyhelminthes

Answer 13

Most provided by surrounding aqueous medium

The cells between the outer surface and the gut provide support through acting as packing tissue

Question 14

Radial symmetry

Answer 14

There is symmetry around a central axis- the body can be divided into two hands by any plane that goes through the central axis (round in cross section)

Question 15

Bilateral symmetry

Answer 15

Body can be divided into two equal halves on each side of a central axis - the two halves are mirror images of each other (only on either side if the central axis)