Cells

Pg. 3

What is a cell?

The basic unit of all living things.

All living things are made up of cells!

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Anton VanLeeuwenhoek

The first person to observe living cells.

He was the first to observe blood cells, and protists!QuickTime™ and a

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Robert Hooke

The first person to observe a cell.

He was looking at cork.

He was actually looking at dead cells, and could only see the cell wall.

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The cell Theory

1. All organisms are made up of one or more cells.

2. Cells are the basic units of structure and function in all organisms.

3. All cells come from other cells that already exist

What is a scientific theory?

A scientific theory is based on an experimental hypothesis, and is supported by evidence and data.

What is spontaneous generation?

For thousands of years, people believed that maggots (living things) came from rotting meat (non-living thing).

The idea that life can be spontaneously created any where at any time.

How did Francis Redi’s experiment disprove the theory of spontaneous generation?

Because the maggots did not grow on the meat that was covered by the lid or the gauze. The maggots were only found on the meat that was open to air.

Cell types

After Redi’s experiment, the invention of the microscope and Hooke’s observation of cells, scientists began to investigate living things more in depth. Anton VanLeeuwenhoek was a major player in identifying different cell types with in our bodies and elsewhere.

Red Blood cells

Carry oxygen thoughout the body.

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White blood cells

Make up our immune system, they help us to fight infection.

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Nerve cells

Send messages throughout the body.

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Muscle cells

Allow for movement and flexibility.

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Bone cells

Bones provide support and structure for our body.

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Skin cells

Our skin helps to protect our body.

The image shows healthy skin cells, as well as skin cancer cells.

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Stem cells

Stem cells, especially embryonic stem cells have the remarkable potential to become any other cell type. These are the first cells that begin to develop after fertilization.

Adult stem cells have limited potential, but can develop into other cell types

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Cell size and scale

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