1.2 Concept Check
The cell has a barrier, the cytoplasmic membrane, that separates the cytoplasm from the environment. Other cell features include the nucleus or nucleoid, cell wall, and cytoplasm. Certain key features, such as metabolism and reproduction, are associated with the living state, and cells can be thought of conceptually as both chemical machines and as biological coding devices.
To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.
1.3 Concept Check
Microorganisms exist in nature in populations that interact with other populations in microbial communities. The activities of microbial communities can greatly affect the chemical and physical properties of their habitats. Most of the biomass on Earth is microbial.