The seven characteristics of living organismsSpec 1.1.1
Every living organism, from a bacterium to a blue whale, shows seven characteristics. A non-living thing, such as a car or a flame, may appear to show some of them, but never all seven.
- Movement
- an action by an organism or part of an organism causing a change of position or place
- Respiration
- the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
- Sensitivity
- the ability to detect and respond to changes in the internal or external environment
- Growth
- a permanent increase in size and dry mass
- Reproduction
- the processes that make more of the same kind of organism
- Excretion
- the removal of the waste products of metabolism and substances in excess of requirements
- Nutrition
- the taking in of materials for energy, growth and development
The first letters spell MRS GREN: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition. Learn each definition word for word, because Cambridge mark schemes follow the syllabus wording.
Points that are often marked
- Plants move too. A plant moves when its leaves or flowers change position, even though the whole plant stays in one place.
- Growth means a permanent increase in size and dry mass. A balloon gets bigger when inflated but does not grow.
- Excretion is not the same as egestion. Faeces are undigested food that never entered the body's cells, so they are not metabolic waste.
- Examples of excretion: carbon dioxide from respiration, urea from the breakdown of excess amino acids, and oxygen from photosynthesis in plants.
Common mistake:
Respiration is not breathing. Respiration is a set of chemical reactions in cells that release energy. Breathing only moves air in and out of the lungs.