What is a Cell?

• The basic structural and functional unit of organisms

• Discovered by English scientist named Robert Hooke in 1665​

The Cell Theory

A major idea in modern biology, which says:

• All living things are made of 1 or more cells

• Cells are the basic unit of all living things

• New cells are made from existing cells​

Microscopes

Compound Light Microscope

• Glass lenses and light are used to magnify objects

  • 10x, 100x, 1000x

• Can use on living specimens

Electron Microscopes

• Electrons are blasted at object

  • Can magnify up to 500,000x

• Can only be used on dead specimens

  • TEM Microscope = black and white image

  • SEM Microscope = 3D image

Cell Similarities

All cells on Earth have

• ​Plasma membrane (also called cell membrane)

  • Outer layer that controls what goes in/out of the cell​

• Genetic material (DNA)

  • Instructions for cell activities

Prokaryotic

• ​small

• no membrane bound-organelles

• no nucleus​

• unicellular​

• example - bacteria​

​

Cell Differences

2 different type of cells on Earth

Eukaryotic

• large

• have membrane-bound organelles​

• have a nucleus​

• uni- and multicellular

• example - plants​, animals, fungi

• Central organelle that holds DNA

Nucleus

• Special structures inside Euk cells, that each perform a different function

• Have a separate membrane

​Membrane-Bound Organelles

Eukaryotic Cells

Amoeba Sisters - Prokaryotic vs Eukaryotic Cells

https://www.youtube.com/watch?v=Pxujitlv8wc