Across
1
Our home planet
3
Biological catalyst
5
Fourth state of matter
6
Gas essential for breathing
7
Substance with pH above 7
9
Infectious microscopic agent
10
Center of an atom or cell
Down
2
Unit of heredity
4
Naturally occurring inorganic solid
8
Measure of matter in an object
11
Magnetic metallic element
12
Group of similar cells
13
Tissue that contracts for movement