Cell Theory and Cells 1665 Robert Hooke used

Cell Theory and Cells

1665___________ Robert Hooke used a microscope to examine a thin slice of cork (bark of an oak tree) and saw “little boxes” He called them “CELLS” because they looked like the small rooms that monks lived in called Cells.

1673 Anton van Leeuwenhoek __________________ a Dutch microscope maker was the first to see LIVING ORGANISMS.

1838 German botanist Matthias Schleiden _____________ concluded that “ALL PLANTS are made of cells”

1839 German zoologist ____________ Theodor Schwann concluded that “ALL ANIMALS ARE MADE OF CELLS”.

1855 German medical doctor Rudolph Virchow _________ saw dividing cells in the microscope and reasoned that “cells come from other cells”

1970 American University Biology Professor Lynn Margulis _________ First to see organelles and proposed that there were “structures in cells that had specialized jobs to help the cell function on a larger scale from themselves. ” One of the first recognized female cellular biologists.

CELL THEORY 1) The cell is the most basic unit of life. 2) All organisms are made of cells. 3) All existing cells are produced by other living cells.

CELLS! All cells share certain characteristics. • All cells are enclosed by a membrane. • All cells are filled with cytoplasm. • All cells contain genetic material that oversees cell processes.

2 Divisions of cells based on cellular organization • Prokaryotes- Pro means “before”, Karyote means “nucleus” - So Prokaryotes are “cells that do not have a nucleus”. • Eukaryotes- Eu means “new” Karyote still means “nucleus” - So Eukaryote means “cells that have a nucleus”.

Prokaryotes Bacteria and Archeae are prokaryotes They both have similar characteristics: ØUnbound DNA- Genetic material is not enclosed in a nuclear membrane. ØOrganelles- Special enclosed parts of the cell that have special jobs. Prokaryotes have very few.

Eukaryotes Include protists, plants, animals, and algae. Ø DNA is within a membrane enclosed nucleus. Ø Have LOTS of membrane enclosed organelles that perform life processes for the cell and perform functions for the whole organism. Ø Cells within a multicellular organism can be specialized to perform a specific function. (ie. brain cells and bone cells)