ANATOMY

Detailed explanation-1: -A cell is the smallest unit that is typically considered alive and is a fundamental unit of life. All living organisms are composed of cells, from just one (unicellular) to many trillions (multicellular). Cell biology is the study of cells, their physiology, structure, and life cycle.

Detailed explanation-2: -Cells provide structure and function for all living things, from microorganisms to humans. Scientists consider them the smallest form of life. Cells house the biological machinery that makes the proteins, chemicals, and signals responsible for everything that happens inside our bodies.

Detailed explanation-3: -By the early 1800s, scientists had observed the cells of many different organisms. These observations led two German scientists, named Theodor Schwann and Matthias Jakob Schleiden, to propose that cells are the basic building blocks of all living things.

Detailed explanation-4: -All living organisms are made up of one or more cells, which are considered the fundamental units of life. Even unicellular organisms are complex! Inside each cell, atoms make up molecules, which make up cell organelles and structures. In multicellular organisms, similar cells form tissues.

Detailed explanation-5: -All cells are made from the same major classes of organic molecules: nucleic acids, proteins, carbohydrates, and lipids.