Interaction

1. Animals are the most well-developed

2. They have sense organs , ands systems for coordinating responses

3. And effector organs or systems for excuting other responses

4. Sense organs are receptor ,they contain receptor cells which percive a specif type of stimulus

4.1. ( Light ,vibrations....etc)

4.1.1. And sed a signal to the coordination system , which interpret it as a sensation (image sound...)

5. Photoreceptor organs of animals are eyes

5.1. They have receptor cells that percive light and an eneable sight

5.1.1. They are usually loated in the head

6. TYPES OF PHOTORECEPTOR ORGANS:

6.1. Simple eyes:

6.1.1. They are found in invertebrates .They detect light and eneable sight , they usit to go toward it

6.1.1.1. Compound eyes:

6.1.1.1.1. They are made up of tiny units of ommaatidia , each one have a part of the landscape wi¡hich forms a ''mosaic vew ''

6.1.1.2. Camera-type eye

6.1.1.2.1. Some invertebrates , and almost all vertebrates

6.1.1.2.2. They have a spherical form

6.1.1.2.3. TH¡hey have receptor cells at the real.

6.1.1.2.4. <They permit a clear image of the landscape