Download Cells

January 3, 2017
Aim #26: How do cells arrange
themselves?
Do Now:
Read page 52 in text
• How long is a single nerve cell in your leg??
• Which is bigger, a red blood cell or a human egg
cell?
• H.W. Midterm January 18th
Cells make up all
living things.
More info on size of cells
• the Ostrich egg is the
largest cell on Earth
• It is about the size of a
football
• mycoplasma bacterium is
the smallest cell in the
world.
• It is only ten micrometers
Some Random Cell Facts
• 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 the letter “i”
• Cells are the smallest units of living things that can
perform all of the basic life processes
• WOW
Red Blood cells
Examples of cells
Human Nerve
cell
Sperm Cells
Muscle Cells
Cells: Size & Shape
• Size and Shape depend upon its function.
a) Red blood cells are small and disc shaped to fit
through the smallest blood vessel.
b) Muscle cells are long and thin. When they
contract they produce movement.
c) Nerve cells which carry signals to the brain are
very long.
d) Sperm cell have round bodies with whip like tails
that swim to fertilize egg cells
What is the definition of a cell?
The basic unit of life.
Cells produce tissues
Tissues produce organs
Organs produce organ systems
Organs systems produce organisms
Tissues, Organs, & Systems
• Cells that work together to perform a specific
function form a tissue.
• Just as cells that work together form a tissue,
tissues that work together form an organ.
• Organs that work together to perform a function
form a system. Example: circulatory system.
• Plant cells also form tissues, such as the bark of a
tree. And plant cells work together, forming
organs, such as roots and leaves.
Multi-cellular Organisms
• Plant cells
Have specialized cells
(like people and other
animals) that might
make up roots or stems.
Groups of similar cells form tissue
Tissue works together as an organ
Organs works together as an organism