Across
1
Nerve cell in the brain
4
Center of an atom or cell
5
Our home planet
9
Unit of heredity
Down
2
Icy body with a tail near the sun
3
Compound containing oxygen
6
Biological catalyst
7
Natural satellite of Earth
8
Second lightest element
Nerve cell in the brain
Center of an atom or cell
Our home planet
Unit of heredity
Icy body with a tail near the sun
Compound containing oxygen
Biological catalyst
Natural satellite of Earth
Second lightest element