Study Notes
Life processes are essential functions that distinguish living organisms from non-living things. These processes include movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition, often remembered by the acronym 'MRS. GREN'.
- Movement — the ability of living things to change position or location. Example: A cheetah running fast or plants turning towards the sun.
- Respiration — the process of releasing energy from food using oxygen. Example: Animals breathe in oxygen and release carbon dioxide.
- Sensitivity — the ability to detect and respond to changes in the environment. Example: Plants bending towards light or animals using sense organs.
- Growth — the increase in size and change in form of an organism. Example: Tadpoles growing into frogs or seeds developing into plants.
- Reproduction — the process by which living things produce offspring. Example: Animals laying eggs or plants producing seeds.
- Excretion — the removal of waste products from the body. Example: Animals exhaling carbon dioxide or plants releasing gases through leaves.
- Nutrition — obtaining or making food necessary for energy and growth. Example: Animals eating plants or other animals, and plants using photosynthesis.
Exam Tips
Key Definitions to Remember
- Movement: Change in position or location of an organism.
- Respiration: Process of releasing energy from food using oxygen.
- Sensitivity: Ability to detect and respond to environmental changes.
- Growth: Increase in size and change in form of an organism.
- Reproduction: Production of offspring by living organisms.
- Excretion: Removal of waste products from the body.
- Nutrition: Obtaining or making food for energy and growth.
Common Confusions
- Confusing respiration with breathing; respiration is a chemical process, while breathing is physical.
- Thinking only animals move; plants also show movement by growing towards light.
Typical Exam Questions
- What is respiration? Respiration is the process of releasing energy from food using oxygen.
- How do plants show sensitivity? Plants show sensitivity by bending towards light and growing in response to gravity.
- What is the role of excretion in living organisms? Excretion removes waste products that could be harmful if accumulated.
What Examiners Usually Test
- Understanding of the seven life processes and their importance.
- Ability to give examples of each life process in different organisms.
- Differences between similar processes like respiration and breathing.