Write the features of the following.
a. Arthropoda
b. Echinodermata

a. Features of Arthropoda:

1. Multiple pairs of jointed legs are present which may be variously modified for walking, swimming and capturing food.
2. The body of these animals is divided into head, thorax and abdomen.
3. The body is protected by a hard cover called exoskeleton which is made of chitin.
4. Arthropods also have antennae and compound eyes on their heads.

Examples: Ant, mosquito, cockroach, butterfly, spider, prawn, crab, millipede and scorpion belong to this group.

b. Features of Echinodermata:

1. Echinoderm means 'spiny skinned'. The body of these animals is covered with spines.
2. They show radial symmetry.
3. Their body usually has a central disc from which five or more arms radiate outwards, giving them a star-like appearance.
4. These animals move with the help of tube feet. These are tube-like structures attached to the lower side of their body.

Examples: Star fish, brittle star, sea urchin and sea cucumber belong to this group.