UNIT 5. ANIMALS (3º E.P.)

UNIT 5 – ANIMALS

WHAT IS A VERTEBRATE?

Vertebrates are animals that have a spinal column and a skeleton formed from bones. The skeleton holds up and protects the body.

Classifying vertebrates

We can classify vertebrates in different ways:

●How they breathe

- Some vertebrates breathe in water through gills

- Others breathe air through lungs

- Amphibians can breathe through their skin.

●What they eat

- Carnivores eat other animals. Wolves are carnivores.

- Hervibores eat plants. Cows are herbivores.

- Omnivores eat both plants and animals. (for example: Humans beings).

● How they reproduce

- Oviparous: their babies are born from eggs.

- Viviparous: their babies are born from their mother’s womb.

The five groups of vertebrates and their characteristics

● Fish

- They live in the water.

- They breathe through gills.

- Their skin is scales.

- They have fins to swim.

- Most of them are oviparous.

● Amphibians

- They can live in water and on land.

- Their babies live in the water and breathe through gills.

- The adults breathe through lungs and through their skin.

- They are oviparous.

● Reptiles

- A lot of reptiles live on land and some in water.

- They breathe through lungs.

- Their skin is covered in scales and some have a shell.

- They are oviparous.

● Birds

- They live on land and in the air.

- They breathe through lungs.

- They have feathers and wings.

- They are oviparous.

● Mammals

- A lot of live on land, some in water.

- They breathe through lungs.

- Their body is covered in skin and fur.

- Most are viviparous.

- Their babies feed on their mother’s milk.

WHAT IS AN INVERTEBRATE?

Invertebrates are animals that do not have a spinal column or a skeleton made of bones.

Characteristics in common:

● They have a soft body.

● Many of them have a shell or exoskeleton to protect their soft bodies.

Classifying invertebrates

We can classify invertebrates in similar ways to vertebrates:

●What they eat:

They are carnivores, herbivores or omnivores.

● How they breathe:

Some breathe through their skin, others through gills, and others through lungs.

● How they reproduce:

All invertebrates are oviparous. Their offspring are called larva. When they grow, some of them change shape.

Some invertebrates and their characteristics:

● Jellyfish

- They have simple bodies, in the shape of a bag.

- They have long poisonous tentacles.

● Worms

- They are very long and thin.

- Some live in water, some on land, and some inside other animals.

● Molluscs

- They normally have shells.

- Some live in water, some on the land.

● Arthropods

- They have a hard cover, or exoskeleton, that protects their body.