Which substance is a compound? A. Water B. Gold C. Oxygen D. Hydrogen

Every animal has a distinct body plan. Which of these animals has a radially symmetrical body plan?

The carbon-dioxide content in the Earth's atmosphere before 1500 A. D. was between 200 and 300 ppm. The carbon dioxide content today is about 450 ppm. Which single historical development can be blamed for this increase? Select one: O a.

What does an urn-shaped age pyramid represent? A. a stable population growth B. a low birth rate C. a low death rate D. a growing population

Plesiosaurs swam by using their paddle-like limbs in a manner similar to that of a fish. sea lion. human. none of the above

Which of the following is most closely identical to the formation of twins? A) cell cloning B) therapeutic cloning C) use of adult stem cells D) embryo transfer E) organismal cloning

Many Head Start programs have a community aide who A. tutors at-risk children in the home. B. gives families the money they need to survive. C. connects families to community resources they need. D. represents families at family/teacher conferences.

Stranded on an island, you have two sources of water to drink: salty ocean water and contaminated fresh water. explain your choice of drinking water and indicate why your selection is the best choice.

How are a hypothesis a prediction and an experiment related

Two species of garter snakes live in the same geographic area. One lives mainly in water and the other mainly on land; therefore, they rarely encounter each other and do not interbreed. What type of isolation is this?

Matter that has a definite column but no definite shape is a