Explain why humans need a circulatory system to transport oxygen, while single-celled organisms like the amoeba do not.

Which statements describe disadvantages of using natural gas as an energy source? Check all that apply. It is expensive to use. It is hard to stop using. It is a nonrenewable resource. It is damaging to the environment.

The survival of organisms best suited to a particular environment is known as

Isotopes of uranium are the most common fuel used in nuclear power plants. True / False

When recombinant DNA is inserted into the genome of a host organism, what's created?

Imagine you are a scientist testing how exercise can affect a persons heart rate. What is the independent variable and the dependent variable of your experiment?

Charles Goodyear was a scientist who was looking for ways to keep rubber from melting in the summer heat and becoming brittle in the winter cold. He discovered the solution by accident when someone left a sample of rubber and sulfur on the stove.

Discuss why scientists know so little about Precambrian Earth

If two elements are in the same chemical family then what can be predicted about their Spectra

Which feature cause a gap in the geologic record a. extrusion b. fault c. intrusion d. unconformity

Which of the following correctly describes a way in which Earth's atmosphere interacts with the geosphere? It contains gases that living organisms breathe. It contains gases that trap incoming solar radiation.