CHAPTER 7 History of the Cell: At least to Our Knowledge

Friday, 9/26/14 Learning Target: Know the three aspects of the Cell Theory. Learning Outcome: I will know how the cell theory was developed and the scientists involved. U

Lenses During the 1st century A.D., Roman glassmakers discovered the first magnifying lens. Lens is from the latin for lentil. Lenses were not used much until the end of 13th century when they were used to make eye glasses.

The Microscope is invented!!! 1590 – Hans and Zaccharias Janssen put several lenses in a tube and saw objects at the end of tube were enlarged. This was the first compound microscope (which is a microscope that uses two or more lenses). Galileo invented the focus.

Cells Are Discovered! 1665 – Robert Hooke looks at a slice of cork under his microscope. The small chambers reminded him of tiny rooms or “cells”!

Cells Are Discovered! 1674 – Anton van Leeuwenhoek built a simple microscope that magnified over 200 times! He discovered bacteria, protists, sperm cells, blood cells and many more.

More Cell Discoveries 1838 – Matthias Schleiden concludes that all plants are made of cells – Theodor Schwann concludes that all animals are made of cells – Rudolph Virchow proposes that all cells come from existing cells.

1)All living things are made up of cells. 2)Cells are the basic units of all living things. 3)New cells are produced from existing cells. Cell Theory – 3 Parts

Structure of Cells Improved microscopes in the 1930’s allowed for observing cells with greater detail. Cells are made up of smaller parts called organelles.

Two Types of Cells Prokaryote: DNA is just floating around inside the cell. Eukaryote: DNA is contained within a nucleus. Generally larger and more complex.