Discovery of Cells and The Cell Theory

Some Random Cell Facts  The average human being is composed of around 75 Trillion individual cells  It would take as many as 50 cells to cover the area of a dot on the letter “ i ”  Cells in the human body have life spans from a few days, a year, and as long as you live  When cells are no longer able to do their job they self destruct

Vocabulary  Cell-  Cell- the smallest functional and structural unit of life  Cytology-  Cytology- the study of cells  Life  Life is defined as the highly organized cellular condition that is born from pre-existing life; Life requires energy to carry on processes such as: ○ Moving ○ Reproducing/Repairing ○ Sensitive (responding) ○ Nutrition (eating) ○ Excrete ○ Respiring ○ Growing

Discovery of Cells Zacharias Janssen  In the 1590s, a Dutch eyeglass maker named Zacharias Janssen used two lenses mounted in adjustable tubes that compounded (or doubled) the magnification of the image  Thus, the compound microscope was born

Discovery of Cells Robert Hooke  English Scientist, Robert Hooke, discovered cells while looking at a thin slice of cork.  He described the tiny boxes or compartments as “cells” after the name of the rooms that monks lived in Micrographia Micrographia  Wrote a book about his findings called Micrographia Micrographia

Discovery of Cells Anton von Leeuwenhoek  1673, Dutch scientist Anton von Leeuwenhoek described microorganisms in pond water  He used a handmade microscope (300x) to observe many tiny things moving around in the pond water  He called them “animalcules”

200 Yr Gap  After the Discovery of cells, there was a gap of about 200 years in which cell research was slowed considerably Spontaneous Generation  It was mostly due to the continued belief in Spontaneous Generation (or the belief that life came from non-living matter)

Spontaneous Generation Disproved Francesco RediLorenzo Spallanzani Louis Pasteur  Thanks to the efforts of Francesco Redi, Lorenzo Spallanzani and Louis Pasteur, whose experiments largely disproved Spontaneous Generation, scientists were able to continue to study cells the Cell Theory  This lead to the Development of the Cell Theory

Development of the Cell Theory  With the invention of the microscope and the contributions of many scientists, a very important question was answered in the 1850’s. The question was: Where do cells come from?

Development of Cell Theory all plant parts are made of cells  German Botanist, Matthias Schleiden, concluded that all plant parts are made of cells all animal tissues are made of cells.  German physiologist, Theodor Schwann, who was a close friend of Schleiden, stated that all animal tissues are made of cells.

Development of Cell Theory Rudolf Virchow cells must come from existing cells.  Rudolf Virchow, a German physician, after studying diseases, concluded that cells must come from existing cells.

The Cell Theory Complete  The 3 Basic Parts of the Cell Theory: 1. All organisms are composed of one or more cells. 2. The cell is the basic unit of structure and function in living things. 3. All cells come from existing cells.

Cell Theory Concept #1 Concept #1: A polar bear is made up of many cells! Concept #2 Concept #2: Different cells in a polar bears body does different jobs. Example: Fat cells provide insulation and energy, while red blood cells carry oxygen. Concept #3 Concept #3: All polar bears cell came from a single living cell. They divide and they grow to replace old dead cells!

How Has The Cell Theory Been Used?  The basic discovered truths about cells, listed in the Cell Theory, are the basis for things such as: Disease/Health/Medical Research Treatments Cancer Vaccines Sports Medicine Physical Therapy Stem Cell Research, etc.

Some Parting Thoughts  It is amazing to think that the cells that make up our bodies are just as alive as we are. Humans are just an intricately designed community of cells, which must work together to survive.  Cells, in my opinion, are one of the strongest cases for intelligent design by our Creator God!

Levels of Cellular Organization  Unicellular Organisms Unicellular organisms are composed of just one cell. They include bacteria, many protozoans, algae, and fungi

Levels of Cellular Organization  Multicellular Organisms Multicellular organisms are made of many cells Most plants, animals, humans, and some algae and fungi are multicellular

Levels of Cellular Organization  Colonial Organisms Colonial Organisms are a collection of similar cells living together, Except for certain specialized reproductive cells, any of the cells could carry on the processes of the organism if they were separated from the colony

Levels of Cellular Organization  Most multicellular organisms are made of cells that are organized into tissues  A tissue is a group of similar cells that work together to perform a specific function.  Several types of tissue that work together to perform a specific function create an organ.  A organ system is made up of a group of organs working together to accomplish life functions.

Levels of Cellular Organization

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