Across
1
Push or pull on an object
3
Tissue that contracts for movement
6
Path of a planet around the sun
7
Center of an atom or cell
8
Group of similar cells
11
Fourth state of matter
Down
1
Preserved remains of ancient life
2
Hottest planet in solar system
4
Substance with pH below 7
5
Naturally occurring inorganic solid
9
Second lightest element
10
Ball of burning gas in space
12
Basic unit of life