Question

question 2 of 10
to test how fertilizer affects tomato plants, a farmer divided a field of young tomato plants into 10 plots of equal size. the farmer then put fertilizer on half of the plots and no fertilizer on the other half of the plots. which factor is being tested in this experiment?
a. amount of fertilizer
b. kind of plants
c. age of plants
d. brand of fertilizer

Explanation:

The experiment is designed to see the effect of fertilizer on tomato plants. The key variable manipulated here is the presence or absence of fertilizer (which relates to the amount - having some vs having none). The kind of plants (all tomato), age of plants (all young), and brand of fertilizer (not mentioned as a variable) are not the factors being tested. The main factor is whether fertilizer is applied (which is about the amount - 0 vs some).

Answer:

A. Amount of fertilizer