An example of a grad-school level question?
The gravitational attraction of the Moon causes which effect on Earth?

An example of a grad-school level question?
Gregor Mendel studied ratios related to traits passed from parent pea plants to offspring pea plants. Mendel used large numbers of plants to avoid "sampling error." This changed the way scientists studied genetics because it included ideas of

An example of a grad-school level question?
In Rutherford's experiment, what caused some high-energy particles to bounce off the metal, while most pass straight through?

An example of a grad-school level question?
At a weightlifting competition, two competitors lifted the same weight to the same height. The second competitor accomplished the lift 2 seconds faster than the first competitor. This demonstrated that the second competitor had more