Part of suns rays used for photosynthesis?

Answer 1

The Sun's 'rays' don't really have parts - it's all just light, which consists of photons. However, the photons emitted by the sun have a range of energies, and the different energies of the photons give rise to the different colours of light that we see. Red light, for example, corresponds to a lower energy than blue light. Apart from different energies, the photons are all exactly the same. The range of colours of visible light, part of the electromagnetic spectrum, is what we see in a rainbow.

The fact that leaves are green means that they reflect green light, so plants are not good at absorbing green light. They are good at absorbing red light though, so a plant under a red lamp should grow better than a plant under a green lamp.

Answer 2

The visible light spectrum, particularly blue and red wavelengths, are the parts of the sun's rays most utilized by plants for photosynthesis. These wavelengths are absorbed by chlorophyll in plant cells to drive the process of converting carbon dioxide and water into glucose and oxygen. Other parts of the light spectrum, such as ultraviolet and infrared rays, do not contribute significantly to photosynthesis.