Question

scientific method practice
1: plant growth and light color
a student wants to test how the color of light affects the growth of bean plants. she places one group under red light, another under blue light, and another under normal white light. all plants receive the same amount of water, soil, and temperature. she measures the height of the plants after two weeks.
some facts: the spectrum of light contains visible and non - visible light that is emitted from our solar system as radiation from our sun. light has different refractional indexes which cause them to bend and produce different colors. plants respond to light due to their chloroplast that houses an enzyme called chlorophyl (pigment/color). some accessory chlorophyl respond to various spectrums of light (carrots leafage is green and the carrot root is orange). this enzyme is activated by light and converts co2 and h2o to glucose (sugar) which allows the plant to grow.
11 what should be a constant? (there might be multiple correct answers)
a amount of water
b color of the light
c growth of the plant
d temperature of the environment

Explanation:

In an experiment testing how light color affects plant growth, constants are factors kept the same to ensure a fair test. The color of light (B) is the independent variable (changed to test its effect). Plant growth (C) is the dependent variable (measured). The amount of water (A) and environmental temperature (D) should be constant as they could affect growth and are not the variable being tested.

Answer:

A. Amount of water, D. Temperature of the environment