February 23, 2015Aim #09: 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. Color Cell Due Wednesday• Field Trip March 20th, 2015• Finish Form Fits Function handout by tomorrow

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

Examples of cellsRed Blood cells

Human Nerve cell

Muscle Cells

Sperm 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 tissueGroups of similar cells form tissue

Tissue works together as an organTissue works together as an organ

Organs works together as an organismOrgans works together as an organism