CELL THOERY

Sun Hwa Dong

CELL

Cell Theory• All living things are

composed of cells.• Cells are the

smallest unit of life.

• All cells are from pre-existing cells by cell division.

History of Cell Theory• Robert Hooke- 1st discovered the cell• Antony Van Leeuwenhoek-1st

observed a living cell using microscope.• Schleiden & Schwaan- “Plants and

animals are made of 'independent, separate beings' called cells.”

Modern Interpretation

+ Original Cell Theory 1.The energy flow take place within cells.2.Cells contain DNA that is inherited from

cell to cell in the progress of cell division.3.All cells are basically identical in chemical

composition in organisms of similar species.

4. The total activity of independent cells decides the activity of an organism.

Unicellular organisms

• Metabolism• Response• Homeostasis • GrowthReproductionNutrition

Multicellular organisms

• Specialized for specific function: differentiation

• Uses genes in nucleus, but not others: gene is being expressed

• Ex: Red blood cell carries oxygen around the body

Bibliography

• Study Guide pg 3

• Course Companion pg 4

• www.studystack.com/flashcard-29229

• en.wikipedia.org/wiki/Cell_theory

• scienceaid.co.uk/biology/plants/cells.html

• lgfl.skoool.co.uk/examcentre.aspx?id=208

Vocabulary

• Cell membrane: a thin structure that surrounds both plant and animal cells and its main job is to determine what can enter and exit the cell.

• Cytoplasm: jelly-like substance between cell membrane and nucleus.

• Mitochondria: “power producer” of a cell. • Metabolism: chemical reactions inside the cell,

including cell respiration to release energy • Homeostasis: keeping conditions inside the

organism within tolerable limits