The Cell

Sixth Grade

Teaching Message 1: All living things are made up of building blocks called

cells.

• All living things are made of building blocks called CELLS.

• Humans, plants, animals, and bacteria are made up of one or many cells.

• Where do you think cells are located in our body? – EVERYWHERE!!!– Humans are made up of cells that work together

and build muscle, bones, skin, and other organs.

Teaching Message 2: Cells are incredibly small – so small that

microscopes are needed to magnify them so that we can see them.

• How many cells are in the human body?– 10 TRILLION!!! (10,000,000,000,000)

Animation: “How big is a cell?”

• http://www.cellsalive.com/howbig.htm

Teaching Message 3: Cells divide and make more cells to help us grow and

repair in a process called mitosis.• Fertilized egg: the result of the fusion of an

egg (from the mother) and a sperm (from the father)

• Mitosis: the process through which cells divide– Each cell divides into two identical cells.– Many cells in the human body continuously die

(like those in our bones, blood, and skin). Mitosis allows for those cells to be replaced

– One exception is nerve cells, or neurons. Most do not divide.

Mitosis, Tumor Cells, and Cancer Cells

• Mitosis is strictly regulated. However, sometimes the process is defective and cells divide uncontrollably. These cells become tumor cells which eventually crowd normal cells. If these cells continue to grow and spread, they become cancer cells.

Animation: Mitosis

• http://www.youtube.com/watch?v=GO5YN_t1fqw

Teaching Message 4: All cells have the same basic parts to do specific tasks,

including the cell membrane, nucleus, mitochondria, and endoplasmic

reticulum.

The Animal Cell

Nucleus

Mitochondria

Cytoplasm

Cell Membrane

Endoplasmic Reticulum

Teaching Message 5: Cells differentiate to become specialized

cells to carry out specialized functions to result in many different types of

cells such as muscle cells, nerve cells blood cells, and others.

The Nerve Cell

Red Blood Cells

Muscle CellsMuscle Cells

Egg and Sperm CellsEgg and Sperm Cells

Teaching Message 6: Different cell types group together to form organs and organ systems. All systems work

together to form a living and functional organism.

• Organs: formed from specialized cells– Heart, lungs, brain, stomach, etc.

• Organ system: made up of organs that work together to perform a particular task – For example, the digestive system is made up of

the mouth, esophagus, stomach, small intestines, large intestines, etc.

Review: Teaching Messages

• 1: All living things are made of cells.• 2: Cells are very small.• 3: Cells divide and make more cells to help us

grow.• 4: All cells have the same basic parts to do

specific tasks.• 5: There are many different types of cells in our

body doing many different jobs.• 6: Cells form organs, which form organ systems.