highschool/Grade 10/Science/SNC2DZ/Unit 2: Biology.md

Unit 2 Biology

• Tissues
• Organs,
• Systems of living things

Celular Biology

A person contains roughly 100 tillion cells - Cells are roughly 20 \(`\um`\) (micrometer, \(`10^{-6}`\) m), around 250 cells / cm

Cell Theory

1. All living things are composed of cells
2. Cells are the basic units of living organisms
3. All cells came from pre-existing cells

Types Of Cells

Prokaryotic cell: Meaning before/lacking nucleus

Eukaryotic cell: Means complete nucleus

Part Of Cell	Prokaryotic	Eukaryotic
DNA	In nuclear region	Usually in membrane, bound nucleus
Size	Usually smaller	Usually larger
Organelles	Not membrane-bound, smaller	Membrane-bound, more complex
Organization	Usually single-celled	Often multicelled
Metabolism	May not need oxygen	Usually needs oxygen to exist