Across
1
Nerve cell in the brain
5
Disturbance that transfers energy
6
Curved glass that refracts light
7
Unit of power
8
Path of a planet around the sun
10
Molten rock beneath Earth surface
Down
2
Our home planet
3
Preserved remains of ancient life
4
Element found in all living things
9
Unit of heredity
11
Amplified beam of light