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

LifeLife is defined as the highly organized cellular condition that is born from pre-existing life; Life requires energy to carry

on processes such as: ○ MMovingoving○ RReproducing/eproducing/RRepairingepairing○ SSensitive (responding)ensitive (responding)○ NNutrition (eating)utrition (eating)○ EExcrete xcrete ○ RRespiringespiring○ GGrowingrowing

Discovery of Cells

In the 1590s, a Dutch eyeglass maker named Zacharias JanssenZacharias 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

1665- English Scientist, Robert HookeRobert 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

Wrote a book about his findings called Micrographia

Discovery of Cells 1673, Dutch scientist Anton von Anton von

LeeuwenhoekLeeuwenhoek 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

It was mostly due to the continued belief in Spontaneous Generation Spontaneous Generation (or the belief that life came from non-living matter)

Spontaneous Generation Disproved

Thanks to the efforts of Francesco Francesco RediRedi, Lorenzo SpallanzaniLorenzo Spallanzani and Louis Louis PasteurPasteur, whose experiments largely disproved Spontaneous Generation, scientists were able to continue to study cells

This lead to the Development of the Cell the Cell TheoryTheory

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 1838- German Botanist, Matthias Schleiden,

concluded that all plant parts are made of cellsall plant parts are made of cells 1839- German physiologist, Theodor

Schwann, who was a close friend of Schleiden, stated that all animal tissues are all animal tissues are made of cells.made of cells.

Development of Cell Theory 1858- Rudolf VirchowRudolf Virchow, a German physician,

after studying diseases, concluded that cells cells must come from existing 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 #1Concept #1: A polar bear is made up of many cells!

Concept #2Concept #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 #3Concept #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 TreatmentsCancerVaccinesSports MedicinePhysical TherapyStem 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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