The History of Cell Biology
Objectives Name the scientists who first observed living and nonliving cells Summarize the research that led to the development of the cell theory State the three principles of the cell theory Explain why the cell is considered to be the basic unit of life
Important Vocabulary Cell Light microscope Nucleus Cytoplasm Cell theory
With a Partner Determine which of the following is made of cells and be ready to defend your answers: Baseball bat Dandelion Glass Brick Stone Beetle Cork Gecko
Discovery of the Cell All living things are made up of one or more cells A cell is the smallest unit of life Starting in the 17th century, scientists were able to use microscopes to study the minuet world around them
Robert Hooke Was an English scientist In 1665, he was the first person to see and name cells He did this by using a light microscope, which is an instrument that uses optical lenses to magnify objects by bending light rays He described cells as “little boxes” But why did he call them cells?
Hooke The cork cells were empty Why?
Anton van Leeuwenhoek Was a Dutch trader who dabbled in natural science In 1675, he was the first person to observe living cells Leeuwenhoek made microscopes that were simple and tiny He ground lenses so precisely that the magnification was 10 times that of Hooke’s instruments
What Leeuwenhoek Saw: We call them protists today Vorticella Spirogyra We call them protists today Leeuwenhoek call them _______________ animalcules
Robert Brown Was a Scottish botanist In 1833, he discovered a central structure within cells This structure became known as the ___________ nucleus
Felix Dujardin Was a French biologist In 1835, he first identified protoplasm in living cells Protoplasm is also known as _______________ cytoplasm
Matthias Schleiden Was a German botanist In 1838, he proposed the hypothesis that all plants are made of cells
Theodor Schwann Was also a German biologist In 1839, he proposed the hypothesis that all animals are made of cells.
Rudolf Virchow Was a German pathologist In 1855, he proposed that cells reproduce to form new cells
The Cell Theory From the work of all these scientists the three tenants of the cell theory were developed!
ALL LIVING THINGS ARE COMPOSED OF CELLS Tenant 1 ALL LIVING THINGS ARE COMPOSED OF CELLS
CELLS ARE THE BASIC UNITS OF STRUCTURE AND FUNCTION OF LIVING THINGS Tenant 2 CELLS ARE THE BASIC UNITS OF STRUCTURE AND FUNCTION OF LIVING THINGS “They’re the building blocks of LIFE!”
Tenant 3 NEW CELLS ARE PRODUCED FROM EXISTING CELLS
1665 1827 1855 1857 1897 1996 2004 Hooke observes cork cells Karl Von Baer discovers the mammalian egg 1855 Virchow adds to the cell theory 1857 Kolliker describes mitochondria in muscle 1897 Golgi discovers the Golgi apparatus in cells 1996 Dolly the sheep is cloned 2004 Tissue engineering is used to grow new skin and bone for transplant