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.
9 what is the independent variable?
a amount of water
b color of the light
c growth of the plant
d temperature of the environment

Explanation:

In an experiment, the independent variable is the factor that is manipulated. Here, the student is testing how light color affects plant growth, so she changes the light color (red, blue, white) while keeping other factors (water, soil, temperature) constant. The growth of the plant is the dependent variable (what's measured), and water amount/temperature are controlled variables. So the independent variable is the color of the light.

Answer:

B. Color of the light