Skip to page content

Diversity in the Animal Kingdom — Part 2: Chordates

Beta

Lesson

The Chordates

Part 2 — animals with a notochord, and their five classes.

In this lesson you will

State the distinguishing features of the five classes of vertebrates
Give examples of each class
Classify a given vertebrate into its class with reasons

Concept

What makes a chordate

Table of the features of chordates
Feature	What it is
Notochord	A stiff supporting rod along the back, replaced by the backbone in vertebrates
Dorsal hollow nerve cord	The spinal cord, lying along the back
Pharyngeal gill slits	Slits in the throat, at least in the embryo
Other signs	Heart on the belly side; a tail behind the anus at some stage

Concept

Pisces and Amphibia

Table comparing fishes and amphibians by habitat, skin, breathing, heart and examples
Feature	Pisces (fishes)	Amphibia
Habitat	Water only	Land and water
Skin	Covered with scales	Moist, smooth, without scales
Breathing	Gills	Skin and lungs; gills in the young
Heart	Two chambers	Three chambers
Examples	Rohu, shark, seahorse	Frog, toad, salamander