Consider the research question, "Does the nitrate concentration in soil affect the size of leaves on an oak
tree? Which of the following choices correctly identifies the variable that would need to be controlled
for the experiment?
a. Nitrate concentration and volume of water given to the tree
b. Leaf size and species of tree
c. Volume of water given to the tree and species of tree
d. Leaf size and nitrate concentration
tree? Which of the following choices correctly identifies the variable that would need to be controlled
for the experiment?
a. Nitrate concentration and volume of water given to the tree
b. Leaf size and species of tree
c. Volume of water given to the tree and species of tree
d. Leaf size and nitrate concentration