A hexahedron (plural: hexahedra) is any polyhedron with six faces. A cube, for example, is a regular hexahedron with all its faces square, and three squares around each vertex. There are seven topologically distinct convex hexahedra, one of which exists in two mirror image forms.
Some bacteria that can help the environment are called decomposers. They are nature's recyclers! They return basic chemicals to the environment for living things to reuse! For example, the leaves of many trees die in the Autumn and drop to the ground.ome bacteria that can help the environment are called decomposers. They are nature's recyclers! They return basic chemicals to the environment for living things to reuse! For example, the leaves of many trees die in the Autumn and drop to the ground.
The cell wall is a tough, flexible and sometimes rigid layer that surrounds some types of cells. It surrounds the cell membrane and provides these cells with structural support and protection. In addition, the cell wall acts as a filtering mechanism.A major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell. Cell walls are found in plants, fungi and prokaryotic cells but not in mycoplasmas.round the outside of the cell membrane is the bacterial cell wall. Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids.