Cover Sheet Cut and discard this bottom portion.
Atoms are the basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. Improve In the 5th cent. B.C. the Greek philosophers Democritus and Leucippus proposed that matter was made up of tiny, indivisible particles they called atom, or in Greek "a-tomos".
Atoms Cut and discard this bottom portion.
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. The Italian, Amadeo Avogadro believed that there were three different types of molecule including 'elementary molecules' (atoms).
Molecules Cut and discard this bottom portion.
An organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer. Camillo Golgi
Organelles Cut and discard this bottom portion.
The cell is the basic structural and functional unit of all known living organisams. Robert Hooke invented an microscope in 1667. He studied various objects with it like wood, he put a small piece of cork under the microscope and found small square things, which reminded him of jail cells.
Cells Cut and discard this bottom portion.
Tissue is a cellular organizational level intermediate between cells and a complete organism. Jean Dausset discovered the tissue. He was born October 19, 1916 he died June 9, 2009. He was a French immunologist.
Tissues Cut and discard this bottom portion.
An organ is a collection of tissues joined in structural unit to serve a common function.
Organs Cut and discard this bottom portion.
The organ system is a group of organs that work together to perform a certain task.
Organ Systems Cut and discard this bottom portion.
an organism is any contagious living system