What is biology?
Biology is the study of living things (organisms) and how they live, grow, reproduce and relate to their surroundings. Biologists study everything from tiny bacteria to elephants and forests. Biology helps in medicine, farming, conservation and food production.
| Branch | Studies |
|---|---|
| Botany | plants |
| Zoology | animals |
| Microbiology | microscopic organisms such as bacteria |
| Ecology | how living things relate to each other and their environment |
| Genetics | inheritance |
| Physiology | how the body works |
Characteristics of living things
All living things carry out seven life processes. A helpful memory aid is MRS GREN.
| Letter | Process | Meaning |
|---|---|---|
| M | Movement | change of position or part of the body |
| R | Respiration | releasing energy from food |
| S | Sensitivity | detecting and responding to changes |
| G | Growth | getting bigger and more complex |
| R | Reproduction | making new individuals |
| E | Excretion | removing waste made by the body |
| N | Nutrition | taking in or making food |
Scientific investigations
Biologists answer questions by investigating: ask a question, make a hypothesis, test it with a fair experiment, record results and draw a conclusion. In a fair test only one factor (the variable) is changed.
Try itSeeds and temperature
A class tests how temperature affects the germination of bean seeds. This simple model shows the usual pattern: seeds germinate best at a warm temperature and poorly when it is too cold or too hot.
Key terms
- Organism
- A living thing.
- MRS GREN
- Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.
- Hypothesis
- A testable suggestion.
- Variable
- A factor that can change in an experiment.
Summary
- Biology is the study of living things and has many branches.
- All living things show MRS GREN.
- A fair investigation changes only one variable at a time.