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LIVING THINGS


A living thing interacts with its surroundings. All living things share some basic characteristics. How many of these characteristics can you indentify in these photos?


CHARACTERISTICS OF LIVING THINGS

All living things  share these characteristics:




Nutrition: living things need food to obtain energy. Most plants use sunlight to make their own food. Animals eat plants and other animals.
All living things take nutrients from their environment and change them into energy. Living things need energy in order to grow and develop. Defferent organisms use different methods to get the energy they need.
Plants are producers. They make their food by taking in organic substances from their environment and transforming them into a plant food called glucose. This process is called photosynthesis.
Animals are consumers. They can´t manufacture their own food, so in order to obtain the energy they need, they must feed on other living things.
Descomposers are living things which feed on the remains of dead plants and animals. Fungi and bacteria are examples of decomposers. 


Respiration: Living things exchange gases with the environment. Animals take oxygen from the air, and give out carbon dioxide.

Excretion: living things produce waste. Humans get rid of their waste when they go to the toilet, perspire (sweat) and when they breathe out.

Reproduction: Living things produce young. These new living things continue to live after their parents die.
This is the process that allows living things to create new living things that will grow to be similar to themselves. Reproduction is essential for the contiation of the species. 
Different living things reproduce in different ways. Lions have young, called cubs, that grow to be adult lions, butterflies lay eggs that hatch as caterpillars and develop into adults, and some bacteria divide to make copies of themselves.

Growth: Living things use energy from fook to grow. When living things grow, they get bigger and they change.

Movement: Living things can move. Plants can only move some parts very slowly but many many animals can run, jump, walk, swim or fly.

Interaction: Living things interact with the world around them. Most living things react to touch, light, temperature and sound.
All living things interact with their environment. A change in the environment can cause a reaction. We call this change a stimulus, and we call this reaction a response. When we touch something very hot, our response is to move our hand away.
Animals can use their sense organs to detect stimuli. Although some plants, such as the Venus Fly trap, have basic sense organs, most plants have no sense organs. Plants do, however, grow towards light and plants´roots grow towards water.

CELLS

All living things are made up of very small units called cells. Cells are the building blocks of life.
A cell is the smallest living unit which makes up a living thing. We need a microscope to see cells because the´re very small. A microscope is an instrument which makes objects look many times bigger.
Some living things, or organisms, have only one cell. These are unicellular organisms. Other organisms are made up of many cells and are called multicellular organisms. Humans are multicellular. There are more than ten billion cells in the human body.

Because cells are living things, they perform the life processes of nutrition, reproduction and interaction. They take in nutrients and they reproduce by dividing into two again and again.

Cells can be different shapes and sizes. Different cells carry out different functions. Muscle cells look very different from nerve cells.

HOW ARE LIVING THINGS ORGANISED?

 
A cell is the smallest living unit.
Cells that carry out the same function group together to form tissue. Muscle tissue is made up of many muscle cells grouped together.

Tissue groups together to form organs. Organs, such as the heart, contain different types of tissue which work together to perform a particular function.

Organs that work together form systems, such as the circulatory system.

When all the systems work together, they form an organism for example, a human body (a person).

An organism is a living thing.

THE KINGDOMS

Living things can be classified into five groups called Kingdom. Living things, or organisms, in one kingdom share similarities and are different from organisms in other kingdoms.

All living things in the Monera kingdom are unicellular, so they all consist of a sigle cell. Unicellular organisms can be bound on land, in the air, in water and inside other living things. Bacteria belong to the Monera Kingdom. Bacteria can be helpful or harmful. Some bacteria can cause illnesses, while other bacteria are used to make food, such as cheese and yoghurt. Some bacteria feed on dead plants and animals.

Living things in the Protist Kingdom are usually unicellular, but some protists are multicellular. Like bacteria, protist can be helpful or harmful. Most protists are found in water. The Amoeba is a unicellular protist, which takes in its food by absorbing it. Algae is a protist that can be unicellular or multicellular.



Members of the Fungus Kingdom can also be either unicellular or multicellular. Yeast is an example of a unicellular organism, and mushrooms are examples of multicellular organisms. Fungi can´t make their own food. They take the nutrients they need from the remains of dead plants and animals.


All plants in the Plant Kingdom are multicellular organisms. They make their own fook by taking energy from the sun. This process is called photosynthesis. During photosynthesis, plants produce oxygen, which is released into the air. Plants can´t move around, but they can move certain parts, and they can react to stimuli, such as light and water. Some algae can be classified as plants because they perform photosynthesis. We can classify plants into two smaller groups: flowering and non-flowering plants.

All animals in the Animal Kingdom are multicellular. They can´t make their own food, so they get the energy they need to survive by feeding on other living things. Animals release carbon dioxide  into the air through the process of respiration. Most animals can move around, and they use their sense organs to interact with their surroundings. We can classify animals into two smaller groups: vertebrates and invertebrates.






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