Question

Dr. Johnson wants to examine whether a new drug improves the memory of older rats. Just like aging

humans, older rats show signs of poorer memory for new things. Dr. Johnson teaches two groups of rats to
find a piece of food in a maze. One groups of rats is given the new drug while they are learning the maze,
and the second group is not given the drug while learning the maze. One week later, he retests the rats am
records how long it takes them to find the food in the maze.
1. What is the independent (manipulated) variable?
A. age of the rats
B. type of maze
C. length of time it took the rats to find the food
D. the new drug

help on this question

Answer 1

D

Step-by-step explanation:

the only thing that was changed was the group of rats being given the drug.