2. the region on the retina where the optic nerve leaves the eye and where there are no light-sensitive cells. No objects can be seen if their image falls onto the blind spot

3. a coiled tube in the inner ear with sensory hair cells for detecting sound

4. an eye defect which the person cannot see some or all colours due to reduced number of or some defect in one or more of the three types of cone cells

5. light sensitive cells in the retina of the eye for colour vision

6. the process by which the receptors and effectors work together or interact to detect and respond to stimuli

7. the sense organ that detects sound and provides the sensation of hearing, and detects the movement of the body and the position of the head

8. the tissue or organ that carries out a response

9. the sense organ that detects light and forms image of the objects around the organism

10. ability of organisms to detect changes in the external environment and to respond to these changes

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