how do organisms complete? for exsample if some plants get too crowded they what_____ for resources and some plants wil what____. and the plant population wll what_____ in size

Maybe you meant "compete"?

To compete means to try to win or do better than others.

Based on your example (which are plants), when they get crowded, the amount of resources intended for them has decreased to a very small amount. This amount cannot sustain their needs, thus, they start to compete with the other plants in order for them to get enough resources. Each plant has a different absorbing capacity of resources, and those which are "weak" will eventually die since they cannot compete with the "stronger" plants. The death of the "weaker" plants will eventually result to the decrease in the size of the plant population.

Hope this helped. :)