Plywood grades are (best to worst) A, B, C and D for face or front face. The back grades are (best to worst) 1, 2, 3, and 4. Plywood grading standards are published by the Hardwood Plywood & Veneer Association.ardwood Plywood Grades Here's a concise explanation of hardwood plywood grades and what they mean.
Cell (biology) The cell (from Latin cella, meaning small room) is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life that can replicate independently, and cells are often called the building blocks of life. The study of cells is called cell biology.
Medical Definition of Cell. Cell: The basic structural and functional unit of any living thing. Each cell is a small container of chemicals and water wrapped in a membrane. There are 100 trillion cells in a human, and each contains all of the genetic information necessary to manufacture a human being. This information is encoded within the cell nucleus in 6 billion subunits of DNA called base pairs.