Development of the Cell Theory Red Blood Cells Cancer Cells CELL UNIT Development of the Cell Theory White Blood Cells

The average human being is composed of around 100 Trillion individual cells!!! It would take as many as 50 cells to cover the area of a dot on this letter “i”

Characteristics of Living Things Living things are made up of cells. Living things reproduce. Living things are based on a universal genetic code. Living things grow and develop. Living things obtain and use materials and energy. Living things respond to their environment. Living things maintain a stable internal environment. Taken as a group, living things change over time.

Nature of Science The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions. Scientists build upon the work of other scientists.

Discovery of the cell 1665 He called his discovery “cells”. Robert Hooke looked at a thin slice of cork under a microscope . He saw thousands of tiny, empty chambers. Robert Hooke 1665 He called his discovery “cells”.

Discovery of the cell 1674 Anton van Leeuwenhoek I will call them animalcules! Observed tiny living organisms in drops of pond water. Anton van Leeuwenhoek

Discovery of the cell Reported the discovery of the nucleus. 1833 http://www.goldiesroom.org/video_archive.htm Discovery of the cell NUCLEUS 1833 Robert Brown Reported the discovery of the nucleus.

Discovery of the cell Elodea Cells 1839 Onion Cells Leaf Cells Concluded that all plants are made up of cells. Matthias Schleiden

Discovery of the cell 1839 Neurons Concluded with Schleiden that all animals are made of cells. Heart Muscle Cells Theodor Schwann Neurons

Schleiden and Schwann’s Cell Theory The cell is the unit of structure, physiology, and organization in living things. The cell retains a dual existence as a distinct entity and a building block in the construction of organisms. Cells form by free-cell formation, similar to the formation of crystals (spontaneous generation). The third idea of their cell theory was incorrect!!!

"Omnis cellula e cellula" "Omnis cellula e cellula"...  "All cells only arise from pre-existing cells". Discovery of the cell Proposes that all cells come from existing cells. 1855 Rudolph Virchow

The modern tenets of the Cell Theory include: 1. All known living things are made up of cells.

The modern tenets of the Cell Theory include: 2. The cell is structural & functional unit of all living things.

The modern tenets of the Cell Theory include: 3. All cells come from pre-existing cells by division. (Spontaneous Generation does not occur).

Figure 1-10 Spallanzani’s Experiment Section 1-2 Gravy is boiled. Flask is open. Gravy is teeming with microorganisms. Flask is sealed. Gravy is free of microorganisms. Gravy is boiled.

The modern tenets of the Cell Theory include: 4. Cells contains hereditary information which is passed from cell to cell during cell division.

The modern tenets of the Cell Theory include: 5. All cells are basically the same in chemical composition.

The modern tenets of the Cell Theory include: 6. All energy flow (metabolism & biochemistry) of life occurs within cells.