The Discovery of the Cell – Journal Notes

Organization of Life In the 1500s we knew organisms were made of organ systems, organs and tissues. But we didn’t know the basic unit of living things.

Robert Hooke Mid 1600s: observed cork (bark from cork tree) under simple microscope Called what he saw “cells”

Anton van Leeuwenhoek Late 1600s: improved the microscope and observed microorganisms.

Matthias Schleiden In 1838: “all plants are made of cells”

Thomas Schwann In 1839: “all living things are made of cells”

The Levels of Organization of Life

Rudolph Virchow In 1855: “all new cells came from pre-existing cells.” -Evidence against “spontaneous generation”

The Cell Theory Three Parts: All organisms are made of cells. The cell is the most basic unit of life. All existing cells are produced by other living cells.

Technology It was technology (the microscope) that allowed us to see cells. Technology is vital to scientific advances. As technology improves so does our understanding of life, the world, the universe…

The Microscope

Types of Cells Prokaryotic Eukaryotic First living things on the planet. Evolved over 3 billion years ago Simple – No complex internal parts. No nucleus. DNA is circular, not in a membrane. Known as Bacteria. Eukaryotic Animal, Plant, Protista, Fungi. Have a nucleus DNA is surrounded by the nuclear membrane. More advanced and complex than prokaryote cells. Have Organelles.

Types of Cells: Prokaryotes Bacteria

Types of Cells: Eukaryotes Protists

Types of Cells: Eukaryotes Animals Neurons Fat Cells

Types of Cells: Eukaryotes Animals Blood Cells Muscle Cells

Types of Cells: Eukaryotes Plants Leaf cells

Types of Cells: Eukaryotes Fungi Chytrid Fungus