1. The characteristics of life
Chapter 2
The characteristics of life

2. Diversity of Life
Estimated that there are about 10 million different types of living things on earth.
An Organism - is a living thing.
Metabolism - is the sum of all the chemical
reactions in an organism.
If you have fast metabolism you generally
move more quickly. If you have slow metabolism
you generally move very slowly.

3. Continuity of Life
Continuity of Life means that living things arise from other living things of the same type.
For centuries it was though that living things could arise from non-living matter. People saw maggots (baby flies) forming on rotting meat and presumed that the meat made the maggots.
It was not until the 1800s that it was first accepted that life originates only from living things of the same type. E.g. maggots develop from the eggs laid in the meat by flies.

4. Organised into cells, tissues, organs, organ systems and organisms
Life
Life and living things possess all 5 characteristics. These characteristics allow organisms to carry out all the reactions necessary to survive and reproduce.
Organised into cells, tissues, organs, organ systems and organisms
2. Nutrition
3. Excretion
4. Response
5. Reproduction
Cells are the basic level of organisation: these cells
are taken from a human cheek

5. 1. Organisation – Means that living things are composed of cells, tissues, organs and organ systems.

6. 2. Nutrition – is the way organism obtain and use food.
Food is needed for energy and to supply the materials needed for normal life. The sun is the basic source of energy for all nutrition. Energy flows from the sun to plants and then to animals.
3. Excretion
Excretion helps to provide a balance between the outside
and inside environment of an organism.

7. In humans the excretory organs are the skin, lungs and urinary system (kidneys & bladder). The main products excreted are carbon dioxide, salts and excess water.
4. Response
Response is the way in which all living things react to changes in their environment.
Living things have to respond in order to react to changes (or stimuli) in their internal and external environment (surroundings). Response is also called behaviour.

8. To allow for responses animals have structures such as eyes, ears, nose, tongue and skin.
Plant responses tend to be slower and less obvious than animals. Plants grow and move in response to factors such as water, light, gravity, touch and chemicals.
5. Reproduction
It is essential that organisms can produce offspring of their own type or the species will become extinct.
Reproduction can be either Sexual or Asexual

9. Living verses non-living
Living things must display all 5 characteristics of living things to be considered living.