• All organisms are made of cells
• The cell is the simplest collection of matter that can be alive
• All cells are related by their descent from earlier cells
• Cells can differ substantially from one another but share common features

Prokaryotic Cells vs. Eukaryotic Cells

• The basic structural and functional unit of every organism is one of two types of cells: prokaryotic or eukaryotic
• Only domains Bacteria and Archaea are prokaryotic cells
• Protists, fungi, animals, and plants are eukaryotic cells
• Components of all cells
  • Plasma membrane
  • Semifluid substance called cytosol
  • Chromosomes (carry genes)
  • Ribosomes (make proteins)
• Eukaryotic cells are usually larger than prokaryotic

Prokaryotic cells are characterized by having

• No nucleus
• DNA in an unbound region called the nucleoid
• No membrane-bound organelles

Eukaryotic cells are characterized by having

• DNA in a nucleus that is bounded by a membranous nuclear envelope
• Membrane-bound organelles
• Cytoplasm = cytosol + organelles
• Cytoplasm between the plasma membrane and nucleus