Characteristics of Living Organisms (MRS GREN)
Living organisms exhibit seven key characteristics, commonly remembered by the acronym MRS GREN:
- Movement: All living things move, either actively or passively. For example, animals move from one place to another, while plants may move their leaves towards light.
- Respiration: This is the process of converting food into energy. Organisms may respire aerobically (using oxygen) or anaerobically (without oxygen).
- Sensitivity: Living organisms respond to stimuli in their environment. For instance, a plant bends towards light, demonstrating sensitivity to light.
- Growth: All living organisms grow and develop over time. This includes cell division and differentiation, leading to maturity.
- Reproduction: The ability to produce offspring ensures the continuation of a species. This can be sexual or asexual reproduction.
- Excretion: Living organisms eliminate waste products from their bodies. This is crucial for maintaining homeostasis.
- Nutrition: Organisms require nutrients to obtain energy and sustain life. They can be autotrophic (producing their own food) or heterotrophic (consuming other organisms).
Understanding these characteristics helps distinguish living organisms from non-living things.
Key points to remember
- Movement: All living things exhibit movement.
- Respiration: Energy production occurs in living organisms.
- Sensitivity: Organisms respond to environmental stimuli.
- Growth: Living organisms undergo growth and development.
- Reproduction: Organisms can produce offspring.
Worked example
State the characteristics of living organisms according to MRS GREN.
- Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.