1.1-Movement, Sensitivity, Growth
1. Characteristics and classification of living organisms
1.1.1 Characteristics of Living Organisms
Movement:
an action by an organism causing a change of position or place
Description:
- Phenomena in which an organism or some of its parts change placction ie or location by as known as a movement. Organisms change positions by moving the whole body or some parts of the body towards different areas or from one place to another.
Movements can be divided into two types.
Voluntary movement:
can be controlled by the body, such as drinking, eating, sleeping, and running.Involuntary movement:
cannot be controlled and stopped by the body; these occur automatically, such as sneezing and heart pumping, and breathing.
Sensitivity:
the ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
Description:
- Sensitivity can be defined as the ability or power of any living organism to detect or recognize stimulus and respond accordingly.
- Many animals can detect stimuli such as sound, light, pressure, touch, and chemicals in food and environment with specialized sensory cells and organs.
- All living organisms trigger responses after receiving stimuli from external and internal sources, as plants show responses along or against gravity and light. These responses are prolonged and exhibited by plant growth either away or near stimuli.
Growth:
a permanent increase in size and dry mass by an increase in cell number or cell size or both
Description:
- A permanent increase or enhancement in the size and dry mass of living organisms is known as growth. Both cell sizes and cell numbers are increased in this phenomenon, such as the formation of large macromolecules like proteins.
- Plant’s growth process continues throughout their lives, while animals and humans stop growing when they reach a particular size in a certain period
