Across
1
Icy body with a tail near the sun
4
Biological catalyst
5
Infectious microscopic agent
8
Force that attracts objects together
9
Path of a planet around the sun
Down
2
Precious yellow metallic element
3
Tissue that contracts for movement
6
Positive particle in nucleus
7
Push or pull on an object
10
Substance with pH above 7
11
Group of similar cells