10. The smallest level of ecological organization. organism population community ecosystem

## Step 1<br />The question is asking for the smallest level of ecological organization. The options provided are organism, population, community, and ecosystem.<br /><br />## Step 2<br />An organism is a single, individual living entity. This could be a bacterium, a fungus, a protist, an animal, a plant, etc. It is the most basic unit of life and is capable of performing all the functions necessary for life.<br /><br />## Step 3<br />A population, on the other hand, is a group of organisms of the same species living in a particular area. This means that a population is made up of many organisms, but they are all the same species.<br /><br />## Step 4<br />A community is a group of populations of different species living in the same area. This means that a community is made up of many different populations, each of which is made up of many organisms.<br /><br />## Step 5<br />An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting system. This means that an ecosystem is made up of many communities, each of which is made up of many populations, each of which is made up of many organisms.<br /><br />## Step 6<br />Therefore, the smallest level of ecological organization is the organism.