I always had trouble assessing this standard, so I created one test for 1st graders, and another for 2nd/3rd graders. Once we had studied it, these tests were a useful way to see if they really got it.
This meets the standards:
Animals compete for food, shelter, and space.
Plants compete for nutrients and water, sunlight, and space
These files are in Microsoft Word format, and can be edited as needed.