Answer:
1. Cells are the basic building blocks of all living things. Cells also contain the body's hereditary material and can make copies of themselves. Cells have many parts, each with a different function. Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell.
2. Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues.
3. A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism.
