AP BIOLOGY

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).

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: -German scientists Theodore Schwann and Mattias Schleiden studied cells of animals and plants respectively. These scientists identified key differences between the two cell types and put forth the idea that cells were the fundamental units of both plants and animals.

Detailed explanation-4: -All cells are made from the same major classes of organic molecules: nucleic acids, proteins, carbohydrates, and lipids.

Detailed explanation-5: -All living things, or organisms, are made up of at least one cell. Some organisms, such as amoebas, are made up of only one cell and are therefore called unicellular organisms. On the other hand, multicellular organisms, such as humans, are composed of more than one cell.