Introduction to Cells

Cell Size and Scale

Robert Hooke

• Cork Cells

Leeuwenhoek

• Powerful Microscope (for his time)– Rotifers

– Human blood cell

– Bacteria

The Cell Theory

• All organisms are made of one or more cells.• All the life functions of organisms occur

within cells. • All cells come from already existing cells.

Strongest Microscope

• Strongest Microscope

Two Categories of Cells

1. Prokaryotic

2. Eukaryotic

Prokaryotic Cells

• No nucleus• DNA floats around in the cell

• Found in single-cells organisms• Bacteria

Eukaryotic Cells

• Have a nucleus• Have organelles• Found in multicellular organisms

• Fungi, dogs, humans, etc

Organelles

Amoeba Sisters- Prokaryotes and Eukaryotes

Diversity of Cells

• All cells share functions such as obtaining and using energy, responding to the environment, and reproducing

• Cells differ with unique structure and function

Skin Cells

Muscle Cells

Liver Cells

Neurons

Blood Cells

Viruses

• Not prokaryotes or eukaryotes• Have DNA, but are not considered living• Viruses infect host cells, and make the host

cells make copies of the virus DNA