Unit 3.- Animal kingdom: vertebrates and invertebrates
INVERTEBRATES
The main characteristic is that they don't have a backbone. They are divided into three main groups:
INVERTEBRATES
The main characteristic is that they don't have a backbone. They are divided into three main groups:
- Arthropods: insects, myriapods, arachnids and crustaceans.
- Molluscs: gastropods, bibalves and cephalopods.
- Other invertebrate groups: cnidarians, annelids and echinoderms.
A) ARTHROPODS
It is the biggest group of invertebrates. It is divided into: insects, arachnids, myriapods and crustaceans.
1. INSECTS
- Exoskeleton.
- Body has three sections: head, thorax and abdomen.
- Two antennae.
- Six legs.
- Most have wings.
2. ARACHNIDS
- Exoskeleton.
- Body has two sections: head and abdomen.
- Eight legs.
- Most have eight eyes.
3. MYRIAPODS
- Exoskeleton.
- Body has lots of segments.
- Lots of legs.
- Two antennae.
4. CRUSTACEANS
- Thick exoskeleton..
- Most have eight legs and two claws.
- Two eyes.
- Four antennae.
B) MOLLUSCS
They don't have an exoeskeleton. There are three main groups: gastropods, bivalves and cephalopods.
1. GASTROPODS
- Soft body.
- Some have a protective shell.
- Tow eyes on the end of antennae.
- Live on land and in water.
2. BIBALVES
- Soft body.
- Two shells connected at one point.
- Live in water.
3. CEPHALOPODS
- Soft body.
- Most do not have an external shell.
- Large head with tentacles.
- Live in water.
VERTEBRATES
The main characteristic is that they have a spine or a backbone.
There are five groups of vertebrates: mammals, birds, reptiles, fish and amphibians.
Learn more about all of them!
1. MAMMALS
- Reproduction: viviparous. They are born from their mothers' womb. They have live babies and feed them with milk. The only exception are the monotremes: platypus and echidna.
- Breathing: they breathe with their lungs and they need air.
- Food: they can be carnivores, herbivores or omnivores.
- Physical appearance: they have four limbs (legs or flippers) and they are generally covered with hair or fur.
- Habitat: they can live on land or in water.
- Blood: they are warm-blooded.
MONOTREMES: they are mammals but they lay eggs. Then, they feed their babies with milk. They are the platypus and the echidna.
2. BIRDS
- Reproduction: oviparous. Adults incubate the eggs, they keep the eggs warm until they hatch. Some bird feed their babies when they are born.
- Breathing: with their lungs.
- Food: some birds are herbivores, others are carnivores and others are omnivores. You just have to look at their beaks to know.
- Physical appearance: they have wings and feathers. Males have brighter colours than females.
- Habitat: most birds can fly. Some, like the penguin, ostrich or kiwi, can't.
- They are warm blooded.
AMAZING BIRD OF PARADISE AND ITS COURTSHIP DANCE:
3. REPTILES
- Reproduction: oviparous. They lay the eggs on land.
- Breathing: they breathe with their lungs.
- Food: most of them are carnivores. Some of them are omnivores and they eat meat, plants and fruits.
- Physical appearance: they have scales on their body. Most of them have four legs, some don't have legs.
- Habitat: most of them live on land; some of them live in water part of their time.
- They are cold-blooded.
4. FISH
- Reproduction: most of them are oviparous. They lay the eggs in water.
- Sharks, whales and dolphins are viviparous. They have live babies, they breathe with lungs, they cannot breath in the water, so they have to go to the surface to get some air.
- Breathing: they breathe with their gills.
- Food: they can be carnivores, herbivores or omnivores.
- Physical appearance: they have scales on their body. They have fins and a tail.
- Habitat: they live in water.
- They are cold-blooded.
5. AMPHIBIANS
- Reproduction: they are oviparous. They lay soft eggs in water.
- Breathing: when they are babies they breathe with their gills. As adults they breathe with their lungs and through their skin.
- Food: most of them are carnivores.
- Physical appearance: they have moist skin. Frogs have strong back legs and webbed toes (toes joined by skin flap: patas palmeadas).
- Habitat: they live in water and on land.
METAMORPHOSIS OF A FROG: the life cycle of a frog
PLAY MORE GAMES ABOUT ANIMALS
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