A gardener is concerned that her greenhouse is getting too hot from too much light and seeks to shade her plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength. What color should she use to reduce overall light energy but still maximize plant growth?

Blue light

Explanation:

Blue light is a form of ultraviolet light that has a short wave length of 400-500nm but high energy. This short wavelength reduce it direct intensity on plant but the high energy it posses makes it of utmost importance with some other light such as green and red in photosynthesis efficiency. It regulate the opening and closing of stomata for CO2 absorption and water regulation. Blue light regulate plant growth and plants grown with blue light are often short with dark green barks.

because of

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.