A researcher is interested in the effects of nitrate and phosphate on plant growth. He sets up an experiment in which groups of five plants are given 1, 2 and 3 grams of nitrate and 1, 2, and 3 grams of phosphate in all combinations over a period of a month. He makes sure that all the plants receive the same amount of water and sunlight. The researcher measures plant height and weight at the end of the experiment. What is missing in this experimental design?

a) A control
b) An independent variable
c) A dependent variable
d) Temperature of light

Question

A researcher is interested in the effects of nitrate and phosphate on plant growth. He sets up an experiment in which groups of five plants are given 1, 2 and 3 grams of nitrate and 1, 2, and 3 grams of phosphate in all combinations over a period of a month. He makes sure that all the plants receive the same amount of water and sunlight. The researcher measures plant height and weight at the end of the experiment. What is missing in this experimental design?

a) A control
b) An independent variable
c) A dependent variable
d) Temperature of light

emmigrace222 · Answer

well what do you think it is?

emmigrace222 · Answer

A or C you pick :)

anonymous · Answer

A thought it was A, But this is my first biology class and I'm a little rust from summer, I'm not familiar with what exactly a control is...

anonymous · Answer

Oh I looked up the definition of a control and I'm pretty sure that's it because he didn't have a plant with just water. Is that the right track?

emmigrace222 · Answer

yes

emmigrace222 · Answer

ki just got done with biology :)