INTRO TO CELLS
Facts
 Cells are the fundamental units of life.
 All living organisms are composed of
and depend on cells to function
normally.
 Scientists estimate that our bodies
contain anywhere from 75 to 100 trillion
cells.
 Cells do everything from providing
structure and stability to providing
energy and a means of reproduction for
an organism.
There are more bacterial cells
in the body than human cells.
 Scientists have estimated that about 95% of
all the cells in the body are bacteria
Cells contain genetic
material.
 Cells contain DNA
There are many types of
cells.
Different types of cells
reproduce through different
methods.
 Most prokaryotic cells
reproduce by a process
called binary fission
(cloning process)
 Eukaryotic organisms go
through mitosis.
Groups of similar cells form
tissues.
Cells have varying life
spans.
 Cells have different life
spans based on the
type and function of the
cell.
 Certain cells of the
digestive tract live for
only a few days, while
some immune system
cells can live for six
weeks.
 Pancreatic cells can live
for as long as a year.
Cells commit suicide.
 When a cell becomes
damaged or undergoes
some type of infection, it
will self destruct by a
process called apoptosis.
 Apoptosis keeps the body’s
natural process of cell
reproduction in check.
 A cell’s inability to undergo
apoptosis can result in the
development of cancer.
Two Main Types of Cells
 Prokaryotic
 Lack a membrane
bound nucleus
 DNA is not found in the
nucleus
 Shapes: rod, spherical,
spiral
 Bacteria
 Eukaryotic
 Membrane bound nucleus
 Many organelles that perform functions
 Kingdoms: Animalia, Plantae, Fungi, Protista
Plant and Animal Cells
Animal
Plant
 Have a cell membrane
 Cell membrane and
 Nucleus
nucleus
 Have a rigid cell wall to
hold its shape
 Chloroplasts for
photosynthesis
 Other organelles