About how many years ago do scientists suggest that the earth cooled enough for water vapor to condense.

A) 20 millions years

B) 4.6 billion years

C) 4.4 billion years

D) 5.5 billion years

Bottled water companies and many other industries remove water from a ground source and transport it away. What problems arise from this?

Why does prolonged exposure to UV light from the sun or tanning beds increase the risk for getting skin cancer? A. increased exposure to UV light decreases the risk of a mutation occurring B.

Copper, sulfur, and oxygen are examples of

What kind of stem cells can develop into any kind of cells in the human body or the placenta? A. Pluripotent stem cells B. Totipotent stem cells C. Multipotent stem cells D. Unipotent stem cells

Scientists have recently discovered two multicellular organisms with different components in their cell walls. The cell walls have two different polysaccharides, cellulose and chitin.

What happens to Earth when it is farthest from the sun? It moves fastest. It stops rotating. It moves slowest. It stops revolving.

What are two different habitats in a prairie ecosystem and name one organism found in each habitat.

Which level on the energy pyramid has the third most energy? A. primary producers B. primary consumers C. secondary consumers D. tertiary consumers

How do pH affect the stability of double-stranded nucleic acid?

What is the first step in the scientific process