Across
1
Unit of heredity
4
The Red Planet
5
Infectious microscopic agent
6
Natural satellite of Earth
9
Form of thermal energy
10
Biological catalyst
12
Our home planet
Down
2
Absolute temperature scale unit
3
Icy body with a tail near the sun
6
Measure of matter in an object
7
Naturally occurring inorganic solid
8
Ball of burning gas in space
11
Nerve cell in the brain