Across
1
Icy body with a tail near the sun
4
Amplified beam of light
5
Biological catalyst
7
Unit of heredity
Down
2
Substance with pH above 7
3
Gas essential for breathing
5
Our home planet
6
Ball of burning gas in space
Icy body with a tail near the sun
Amplified beam of light
Biological catalyst
Unit of heredity
Substance with pH above 7
Gas essential for breathing
Our home planet
Ball of burning gas in space