Question

1. why would artificial plant - growth lights have a light spectrum that favors blue and red?
2. explain why plants are green.

Explanation:

For question 7:

Plants use chlorophyll (the main photosynthetic pigment) to absorb light energy for photosynthesis. Chlorophyll absorbs blue and red wavelengths of light most efficiently, as these wavelengths provide the optimal energy for the chemical reactions of photosynthesis. Artificial grow lights prioritize these wavelengths to maximize the energy available for plant growth, since other wavelengths (like green) are poorly absorbed and not as useful for the process.

For question 8:

Plants appear green because their primary photosynthetic pigments, chlorophyll a and chlorophyll b, absorb blue and red light wavelengths very effectively but reflect and transmit green light. Since green light is not absorbed by the plant's pigments, it is the wavelength that reaches our eyes, making plants look green.

Answer:

1. Artificial plant-growth lights favor blue and red light because chlorophyll, the key pigment for photosynthesis, absorbs these wavelengths most efficiently to fuel the chemical reactions needed for plant growth, maximizing energy use for development.
2. Plants are green because their chlorophyll pigments absorb blue and red light for photosynthesis, but reflect and transmit green light, which is the wavelength detected by human eyes.