Across
1
Infectious microscopic agent
3
Element found in all living things
5
Biological catalyst
7
Push or pull on an object
11
Icy body with a tail near the sun
13
Nerve cell in the brain
Down
2
Tissue that contracts for movement
4
Particle of light
6
Basic unit of life
8
Unit of force
9
Molten rock beneath Earth surface
10
Absolute temperature scale unit
12
Substance with pH below 7