A researcher conditions a rat to press a lever in an operant conditioning chamber for the positive reinforcement of food. The next day, after being fed a reduced diet, the rat is more interested in smelling the cedar on the cage floor than pressing the lever. This is an example of:

Describe how a student should adjust the microscope to see the cells on a slide more clearly?

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.

Identify any four organelles that should be present in the eukaryotic organism and describe the function of each organelle