<h2>
Answer:</h2><h2>
Cells exist by themselves such as bacteria....</h2>
Whilst Virus are non loving infectious particles and need a living host to reproduce.
The answer is thermal and light energy
Limited resources in an ecosystems would be
Land/territory
<span>Food </span>
<span>Water (in terrestial ecosystems) </span>
<span>Sunlight (mostly for plants) </span>
<span>Nutrition in the soil (again, usually for plants) </span>
