UNIT 2 NATURAL SCIENCE: KINGDOMS OF LIVING THINGS

Classifying living things

Living things are classified into groups, called kingdoms. Living things from the same kingdom share similar characteristics. There are 5 kingdoms:

• Animal kingdom.
• Plant kingdom.
• Fungi kingdom.
• Protista kingdom.
• Monera kingdom.

The Animal kingdom

Animals are multicellular organisms that eat other living things and can move. They are divided in two groups.

• VERTEBRATES: all vertebrates have an internal skeleton made up of bones. This skeleton includes a backbone. Vertebrates are classified into five groups:
• MAMMALS: they are viviparous, their bodies are covered with fur or hair, they breathe with lungs, most mammals have legs and their babies drink mother's milk. For example: dog, whale (lives in the water) and bat (it can fly).
• BIRDS: they are oviparous, their bodies are covered with feathers, they breath with lungs and they have two legs and two wings. For example: parrot, owl, penguin,... 
• REPTILES: they are oviparous, their skin is covered with sclaes, they breathe with lungs and most reptiles have legs. For example: chamaleon, turttle, snake, lizard...
• AMPHIBIANS: they are oviparous, they breathe through gills when they are babies and with lungs when they are adults. Also, they can breathe trough their skin. Amphibians make the metamorphosis. For example: frog, salamander, toad...
• FISH: they are oviparous, their bodies are covered with scales, they breathe through gills and they have fins. For example: shark, salmon,...
• INVERTEBRATES: they don't have an internal skeleton so they don't have backbone too. Invertebrates are classified into six groups:
• SPONGES: they filter seawater through tiny holes to obtain food.
• CNIDARIANS: they have soft bodies with poisonous tentacles to catch their prey.
• WORMS: they have long and soft bodies. They don't have legs.
• MOLLUCS: they have soft bodies and many of them have a hard external shell.
• ECHINODERMS: they are marine animals.
• ARTHROPODS: they have an external eskeleton. They include insects, arachnids, crustaceans and myriapods.

Animals could be clasificate in different ways:

• In relation to whay they eat, they could be:
• CARNIVORES: they only eat meat. For example: lion.
• HERBIVORES: they only eat plants. For example: zebra.
• OMNIVORES: they eat meat and plants. For example: pig.
• In relation to how they reproduce, they could be:
• VIVIPAROUS: they born to the mother's womb.
• OVIPAROUS: they born from eggs.

THE FUNGI KINGDOM

Fungi are different living things from plantas and animals. Like plants, they cannot move about and many of them grow in soil. Like animals, fungi cannot make their own food. Fungi are classified into two groups:

• Unicellular fungi, like yeasts.
• Multicellular fungi, like mushrooms and moulds.

The main parts of a mushroom are the cap, the gills, the ring and the steam.

THE PLANT KINGDOM

Plants are multicellular living things that can make their own food and cannot move about. All plants can be classified into two main groups:

• Non-flowering plants:  they reproduce with spores. There are two types:
• Mosses.
• Ferns.

• Seed - producing plants: they reproduce with seeds. There are two types:
• Gymnosperms: not produce flowers or fruits. They only produce seeds.
• Angiosperms: they produce flowers and fruits which contains seeds.

THE PROTISTA KINGDOM

Protists include 2 different types of organism:

• ALGAE: algae are aquatic living things that can be unicellular or multicellular. They can make their own food. Algae are very nutritious, so they are used as food in many countries. They are also used as fertilizer and to produce cosmetics.

• PROTOZOA: protozoa are unicellular living things that live in aquatic enviroments. They feed on other organisms. Some protozoa can cause diseases, like malaria.

THE MONERA KINGDOM

Moneras are unicellular living things. This kindom includes bacteria.

Bacteria are the smallest and simplest living things, and can only be seen through a microscope. Some bacteria are helpful, like the ones used to make yoghurt, but others are harmful, like the ones that cause cholera.

EXERCISE