Year 1 · Plants and animals · Section 1.1
Organisms
Living things
Biology is the study of life. It focuses on organisms: living things such as humans, other animals, plants, bacteria and fungi.
Organisms carry out seven life processes: respiration, sensitivity, growth, nutrition, movement, excretion and reproduction. Objects such as stones do not carry out life processes and are not organisms.
Taking in and removing substances
Organisms take in substances such as water, nutrients and, in many cases, oxygen. Nutrition supplies nutrients, while breathing helps animals with lungs take in oxygen. Respiration releases energy from nutrients inside cells; it is different from breathing.
Organisms also release substances, for example by breathing out or passing urine. Respiration, nutrition and excretion are essential for staying alive.
Responding to the environment
Organisms detect changes in their surroundings and respond to them. This ability is called sensitivity. Animals use sense organs, such as eyes and ears, to detect changes, and may respond by moving.
These responses help them survive, for example by escaping from danger.
Continuing the species
Reproduction and growth allow a species to continue to exist. Offspring grow into adults, which may produce offspring of their own. An individual does not have to reproduce to be alive.
Living, dead and never alive
Living organisms carry out life processes. An organism is dead when its life processes have permanently stopped.
Things that have never been alive, such as stones and air, have never carried out life processes. However, they can affect living organisms. In English, non-living includes both dead things and things that have never been alive.
Glossary
- Dead
- Once alive, but with life processes permanently stopped.
- Living
- Alive and carrying out life processes.
- Life processes
- The seven processes associated with living things: respiration, nutrition, excretion, sensitivity, movement, reproduction and growth. The initials in a different order form the memory aid MRS GREN.
- Never alive
- Describes things such as stones, air and water that have never carried out life processes.
- Organism
- An individual living thing, such as an animal, plant, bacterium or fungus.
Frequently asked questions
What is an organism?
An organism is an individual living thing, such as a human, another animal, a plant, a bacterium or a fungus.
What are the seven life processes?
Respiration, nutrition, excretion, sensitivity, movement, growth and reproduction.
What is the difference between dead and never alive?
Something dead was once alive. Something that has never been alive, such as water, air or a stone, has never carried out life processes. Both are non-living.