Cell Theory

In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers “cells.”

Discoveries leading to cell theory: 1665 – Robert Hooke saw and named cells 1838 – Matthias Schleiden concluded that all plants were made of cells 1839 – Theodor Schwann stated that all animals were made of cells 1855 – Rudolph Virchow concluded that new cells were created only from division of existing cells.

Cell Theory All living things are made of cells Cells are the basic unit of structure and function of living things Cells come from preexisting cells by reproduction

All cells have: Cell membrane – controls what enters and leaves the cell DNA – genetic material

2 categories of cells: Prokaryotes Eukaryotes No nucleus No membrane bound organelles Ex: bacteria Have a nucleus Have membrane bound organelles Ex: Plants, Animals, Fungi, Protists

Prokaryote Eukaryote

1. What are the 3 parts of cell theory? All living things are made of cells Cells are the basic unit of structure and function of living things Cells come from preexisting cells by reproduction

2. What 2 things do all cells have? Cell membrane – controls what enters and leaves the cell DNA – genetic material

3. How do prokaryotes differ from eukaryotes? Prokaryotes do not have a nucleus Eukaryotes do have a nucleus.