1. Which of the following is a biotic factor?
   
   

Asunlight

Bworms

Cwater

Dclimate

1. Nitrogen is used by ____.
   
   

Aplants

Banimals

Cboth a and b

Dneither a or b

1. As you move from level to level in an energy pyramid, energy ____.
   
   

Adecreases

Bincreases

Cstays at the same level

Dis destroyed

1. The part of Earth that supports life is a(n) ____.
   
   

Abiome

Becosystem

Cbiosphere

Dorganism

1. Population ____ can be even, random, or clumped together.