CIE iGCSE Co-ordinated Sciences-B1.1 Characteristics of living organisms - Study Notes- New Syllabus
CIE iGCSE Co-ordinated Sciences-B1.1 Characteristics of living organisms – Study Notes
CIE iGCSE Co-ordinated Sciences-B1.1 Characteristics of living organisms – Study Notes -CIE iGCSE Co-ordinated Sciences – per latest Syllabus.
Key Concepts:
Describe the characteristics of living organisms by defining:
(a). movement as an action by an organism or part of an organism causing a change of position or place
(b). respiration as the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
(c). sensitivity as the ability to detect and respond to changes in the internal or external environment
(d). growth as a permanent increase in size and dry mass
(e). reproduction as the processes that make more of the same kind of organism
(f). excretion as the removal of waste products of metabolism and substances in excess of requirements
(g). nutrition as the taking in of materials for energy, growth and development
CIE iGCSE Co-Ordinated Sciences-Concise Summary Notes- All Topics
Characteristics of Living Organisms
📌 Introduction
- All living organisms (plants, animals, unicellular, multicellular) share seven basic characteristics.
- Easy way to remember: MRS GREN
🔑 The 7 Characteristics
- Movement
Action by an organism (or part) that causes a change in position or place.
Eg: Animals walk, plants bend toward light. - Respiration
Chemical reactions inside cells break down nutrients (like glucose) → release energy.
Energy is needed for metabolism (all life processes). - Sensitivity
Ability to detect and respond to changes in environment (internal or external).
Eg: Eyes detect light, plants sense gravity. - Growth
Permanent increase in size and dry mass.
Happens by increase in cell number, cell size, or both. - Reproduction
Process by which organisms produce more of their own kind.
Ensures survival of species. - Excretion
Removal of waste products of metabolism (e.g. CO₂, urea).
Also removes substances in excess of requirements. - Nutrition
Taking in of materials needed for energy, growth, and development.
Plants: need CO₂, H₂O, ions, light.
Animals: need organic compounds (carbohydrates, proteins, fats), ions, water.
🗂️ Summary Table
| Characteristic | Definition (Short) | Example |
|---|---|---|
| Movement | Action causing change of place/position | Plant shoots bend toward light |
| Respiration | Cell reactions breaking nutrients to release energy | Glucose → ATP |
| Sensitivity | Detect & respond to stimuli | Eye senses light |
| Growth | Permanent increase in size & dry mass | Baby → adult |
| Reproduction | Make more of same kind | Bacteria binary fission |
| Excretion | Removal of metabolic wastes | Humans excrete urea |
| Nutrition | Intake of materials for energy/growth | Humans eat food, plants photosynthesise |
⚡ Quick Recap
Life = MRS GREN
– Movement → change of place
– Respiration → energy release in cells
– Sensitivity → response to stimuli
– Growth → permanent increase in size/dry mass
– Reproduction → making offspring
– Excretion → removal of wastes (CO₂, urea)
– Nutrition → intake of food/water/minerals