AP BIOLOGY

Detailed explanation-1: -All living organisms are composed of structural and functional units called cells. The body of a living organism may be composed of a single cell or many cells. A cellis the smallest unit of life that can replicate independently.

Detailed explanation-2: -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-3: -Yes, all living things are made up of cells. In 1665, Robert Hooke discovered the existence of cells using a microscope, which further paved the way for the discovery of various other microscopic organisms. Some organisms consist of a single cell, for example, the amoeba.

Detailed explanation-4: -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-5: -Living things have a variety of characteristics that are displayed to different degrees: they respire, move, respond to stimuli, reproduce and grow, and are dependent on their environment.