What is sensitivity in living organisms?
The ability of living organisms to detect and respond to changes in their environment.
What is a stimulus?
Any environmental change that triggers a response.
What is irritability?
The capability of organisms to respond to stimuli.
Define taxism.
The movement of an entire organism in response to a stimulus.
What is positive taxism?
Movement of an organism toward a stimulus.
Give an example of phototaxis.
Euglena moving toward light.
What is chemotaxis?
Movement of an organism in response to a chemical stimulus.
Define nastism.
Non-directional movement in plants in response to a stimulus.
What is nyctinasty?
Movement in response to day-night changes, like the opening and closing of flowers.
What is hydronasty?
Plant movement in response to changes in humidity.
Define tropism.
Directional growth of a plant part in response to a stimulus.
What is positive phototropism?
Growth of a plant toward light, as seen in shoots.
What is geotropism?
Growth in response to gravity; roots show positive geotropism.
Define thigmotropism.
Plant growth in response to touch, like in climbing plants.
What is cyclosis?
Movement of protoplasm within cells, as seen in amoeboid movement.
What are pseudopodia?
Lobe-shaped extensions used by Amoeba for movement.
What are cilia?
Short, hair-like structures that facilitate movement, as in Paramecium.
What is the function of flagella?
Long whip-like structures used for movement, as seen in Euglena.
How does Paramecium use cilia?
For movement and directing food into its gullet.
Give an example of an organism that uses flagella for movement.
Euglena or Chlamydomonas.
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