Study Notes
Living organisms share common characteristics such as movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition.
- Movement — action by an organism or part of an organism causing a change of position or place Example: Animals moving their limbs or plants moving towards light (phototropism).
- Respiration — chemical reactions that break down nutrient molecules in living cells to release energy Example: Respiration in cells to release energy for essential functions.
- Sensitivity — ability to detect or sense changes in the environment (stimuli) and to make appropriate responses Example: Animals responding to touch or plants responding to gravity (geotropism).
- Growth — permanent increase in size and dry mass by an increase in cell number or cell size or both Example: Animals and plants increasing in size.
- Reproduction — processes that make more of the same kind of organism Example: Sexual and asexual reproduction.
- Excretion — removal from organisms of toxic materials and the waste products of metabolism Example: Animals exhaling carbon dioxide or plants removing waste by transpiration.
- Nutrition — taking in of nutrients which are organic substances and mineral ions Example: Animals eating food or plants absorbing nutrients from the soil.
Exam Tips
Key Definitions to Remember
- Movement
- Respiration
- Sensitivity
- Growth
- Reproduction
- Excretion
- Nutrition
Common Confusions
- Mixing up gas exchange with breathing
- Confusing egestion with excretion
Typical Exam Questions
- What is the process of respiration? Respiration is the chemical reactions that break down nutrient molecules in living cells to release energy.
- How do plants exhibit movement? Plants can move by growing towards light, a process known as phototropism.
- What is excretion? Excretion is the removal of toxic materials and waste products of metabolism from an organism.
What Examiners Usually Test
- Understanding of the seven characteristics of living organisms
- Ability to distinguish between similar processes like respiration and breathing
- Knowledge of examples of each characteristic in different organisms