An example of a grad-school level question?
Birds that do not receive adequate nutrition during development sing less often and for shorter periods of time as adult birds. Which best describes the outcome of nutritional stress in these songbirds?

An example of a grad-school level question?
Astronomers and biologists study different areas of science. Many astronomers observe far distant objects in the sky. Many biologists study extremely small objects. What do these astronomers and biologists have most in common?

An example of a grad-school level question?
A duck's feathers are covered with a natural oil that keeps the duck dry. This is a special feature ducks have that helps them

An example of a grad-school level question?

Which adaptation often helps an animal attract a mate?