Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy. * The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing (except virus, which consists only from DNA/RNA covered by protein and lipids), and is often called the building block of life. Organisms can be classified as unicellular (consisting of a ingle cell; including most bacteria) or multicultural (including plants and animals).
Humans contain about 100 trillion (1014) cell. Most plant and animal cells are between 1 and 100 pm and therefore are visible only under the microscope. CELL * The prokaryote (prone. : l, pro-AKA-ere-toes ) are a group of organisms whose cells lack a cell nucleus (carbon). * The organisms whose cells do have a nucleus are called eukaryote. (Eh=true, carbon= nucleus) * A tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
Human lung tissue * A heterodox (hetero = “another”, “different” and trophy = “nutrition”) is an organism that cannot fix carbon and uses organic carbon for growth * An authors[a] (“self-feeding”, from the Greek autos “self” and trophy “nourishing”) or “producer”, is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple substances present in its surroundings, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis).