A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure?
A) full-spectrum white light
B) green light
C) a mixture of blue and red light
D) UV light

Question

Quizplus · Accepted Answer

Blue and red wavelengths are the most effective in promoting plant growth and can be produced by LED lights with minimal energy expenditure. Full-spectrum white light provides all wavelengths of light, but also includes green and yellow wavelengths that are less effective for plants. Green light is not absorbed efficiently by plants and therefore not ideal for plant growth. UV light can be harmful to both plants and animals and is not necessary for plant growth.

A Spaceship Is Designed to Support Animal Life for a Multiyear