The Cell Theory A Timeline With permission: bujols via Slide Share
Late 1500’s Late 1500’s Hans and Zacharias Janssen Dutch lens grinders, father and son produced first compound microscope (2 lenses)
Robert Hooke ( 1665) Used light microscope to look at thin slices of plant tissues -- cork Looked empty, like monk’s chamber Called tiny chambers “cells”
Anton von Leeuwenhoek (1673) Looked at pond water organisms First to see living microscopic organisms. Made careful sketches.
Matthias Schleiden -- 1838 German Botanist (studied plants) Viewed plant parts under a microscope Discovered that plant parts are made of cells He concluded: “All plants are made of cells.”
Theodore Schwann -- 1839 “All animals are made of cells.” German scientist who studied animals - zoologist Saw that all animals he studied were cellular so concluded: “All animals are made of cells.”
Rudolf Virchow - 1855 German physician who studied cell reproduction “Where a cell exists, there must have been a preexisting cell.”
Cells A cell is the smallest unit that can perform all the functions necessary for life. All living things are made up of cells. Some living things are made up of only one cell (single cellular). Other living things are made up of many cells (multicellular).
The Cell Theory All living things are composed of one or more cells. The cell is the basic unit of life in all living things. New cells are produced from existing cells.
Cell Similarities Cells come in many shapes and sizes with different duties but … All are surrounded with a cell membrane All cells have hereditary material (DNA) All have cytoplasm and organelles. Cytoplasm is the fluid within a cell which provides a safe environment for the organelles. Organelles are the structures within the cell that have specific duties to make the cell a functioning unit.
Two Types of Cells Eukaryotic Are complex and of different types. Have a nucleus and many organelles. Contain more DNA due to different jobs within the cell. DNA is linear (in a line). Possess a cell membrane or a cell wall. All living things other than bacteria.
Two Types of Cells Prokaryotic Contain no nucleus. Have no membrane covered organelles, but do have ribosomes to make protein. Possess circular DNA. Are bacteria.