Guard cells close up to prevent water loss. These guard
cells will automatically open up if there is a need of water to go out of the
cell. An open stomate allows water to leave through transpiration, guard cells
control the opening and closing of a stomata, stomates will close to reduce
water loss and By opening and closing the stomata on the underside of the
leaves.
As shown in detail in the absorption spectra, chlorophyll absorbs light in the red (long wavelength) and the blue (short wavelength) regions of the visible light spectrum. Green light is not absorbed but reflected, making the plant appear green
