An example of a grad-school level question?
Which cell can survive without the help of other cells?

An example of a grad-school level question?
The water in a pond gets colder one night. Which tool is best to observe its temperature change?

An example of a grad-school level question?
Which of the following is formed immediately after fertilization?

An example of a grad-school level question?
If the solar system were used as a model of an atom, what would the Sun most likely represent?