2. To determine population size in a population of immobile organisms such as plants, or for very small and slow-moving organisms, one could use:

voluntary muscles are controlled by the cerebellum.

producers within ecosystems are essential as they are at the base of the food chain. plants are examples of producers. they use the process of photosynthesis to capture light energy and use it to convert simple inorganic substances (carbon dioxide and water) into organic substances (glucose).