4) All the populations of different species that live a a) A population b) A community c) An ecosystem d) A biosphere

## Step 1<br />The problem is asking us to identify the term that refers to all the populations of different species that live in a specific area. Let's analyze each option:<br /><br />## Step 2<br />### A population<br />A population refers to all the individuals of a single species living in a specific area. This term does not encompass multiple species, so it is not the correct answer.<br /><br />## Step 3<br />### A community<br />A community refers to all the populations of different species living in a specific area. This term includes multiple species, so it is the correct answer.<br /><br />## Step 4<br />### An ecosystem<br />An ecosystem includes all the living organisms (biotic factors) in a specific area, along with the non-living components (abiotic factors) such as soil, water, and climate. This term is broader than just the populations of different species, so it is not the correct answer.<br /><br />## Step 5<br />### A biosphere<br />The biosphere refers to the part of the Earth where life exists, including all the living organisms and the environments in which they live. This term is even broader than an ecosystem, so it is not the correct answer.