Cyanobacteria pumped this into the atmosphere, creating an ozone layer.

Nitrogen

Oxygen

Methane

Ammonia

How is identifying rocks different from identifying the minerals that compose the rocks?

Explain why a somatic cell could not be used for fertilization.

only special bacteria can use nitrogen in our atmosphere and "fix" it so other organisms can benefit. what are theese bacterias called?

On a farm, there has been a sudden spike in the rodent population, causing an increase in crop damage and, as a result, loss of income.

When an acid and base combine what is one property of the product?

The forming and breaking of bonds in a chemical reaction always involves changes in energy what are the 2 options of what happens to that energy?

Demographic transition is the transition from high birth and death rates to low birth and death rates as a country develops from a pre-industrial to an industrialized economic system. A demographic transition involves four stages.

Why does the oxygen atom in a water molecule have a negtive change

Melting wax evaporating gasoline freezing water These changes are all examples of A) nuclear changes. B) physical changes. C) chemical changes. D) energy consumption.

A woman is a natural blonde and her husband has black hair. All their children have black hair. Why do you think that the blonde hair did not appear in any of the children?