4th graders around the world: NATURAL SCIENCE: Living things: Animals

LIVING THINGS: ANIMALS

Do you remember Vertebrates and Invertebrates?

- Vertebrates: Animals with backbone. There are 5 groups of vertebrates. Fish, reptiles, birds, mammals and amphibians

- Invertebrates: Animals with no bones. There are many groups of invertebrates, but the most known are: Insects, arachnids, molluscs, crustaceans, protozoa,...

Vertebrate nutrition

Animals cannot make their own food and they obtain energy by eating other living things, so they care called CONSUMERS

CONSUMERS can be:

Carnivores: They eat meat.

Herbivores: They eat plants

Omnivores: They eat meat and plants.

Do you want to play? Click here and guess the diet of the animals

Vertebrate breathing

All animals need to take oxigen.

- Mammals, birds and reptiles take oxygen from the air. Air passes into the lungs. Waste carbon dioxide leaves the body through the lungs.

- Fish take in oxigen from water. Oxygen is absorbed into the blood through capillaries in gills.

- Amphibians take in the oxigen from water through the gills. During the metamosphosis, the gills close and they develop lungs. Adult amphibians can also absorb oxigen and expel carbon dioxide through their moist skin

Vertebrate reproduction

Animals are born, they grow, they reproduce and they die.

Animals can be oviparous, viviparous and ovoviviparous.

- Oviparous animals: Birds, fish, reptiles and amphibians are oviparous animals. The embryo grows inside the egg. The egg contains all the nutrients it need to grow.

- Viviparous animals: Mammals are viviparous. The embryo develops inside the mother. All babay mammals drink their mother's milk.

- Ovoviviparous animals: These animals produce eggs but the eggs develop and hatch inside the mother. Later, the mother gives birth to the baby. The tiger shark is ovoviviparous.

Revision

Correct the following sentences:

- - A mammal is born from eggs.

- A mammal is born from the mother’s womb

Birds have their body covered with scales.

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- Vertebrate groups are: mammals, birds, reptiles, amphibians and worms

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- An animal that only eats plants is called carnivore.

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- Mammals have their body covered with feathers.

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- Omnivore animals are those who eat meat.

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- Mammals, birds and fish breath through the lungs

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INVERTEBRATES

MAKE THE FOLLOWING QUIZ BY CLICKING HERE

1.- CHARACTERISTICS

Invertebrates all share one characteristic – they do not have a backbone.

We can classify invertebrates into six groups:

1. Arthropods,

2. Molluscs,

3. Echinoderms,

4. Worms,

5. Sponges and

6. Cnidarians.

1. ARTHROPODS

This is the largest invertebrate group. All arthropods have an external skeleton called an exoskeleton. Inside this group we find:

a) INSECTS

b) CRUSTACEANS

c) MYRIAPODS

d) ARACHNIDS

A) . Insects have three body parts:head, thorax and abdomen

All insects have two antennae and three pairs of legs (6 legs) which are joined to the thorax. Most insects have one or two pairs of wings.