Across
1
Infectious microscopic agent
3
Biological catalyst
5
Substance with pH below 7
6
Icy body with a tail near the sun
7
Reddish electrical conductor
8
Element found in all living things
9
Unit of energy
Down
2
Compound containing oxygen
4
Center of an atom or cell
6
Basic unit of life
10
Unit of heredity
11
Push or pull on an object