Cell Theory, Prokaryotic and Eukaryotic Cells, and Endosymbiotic Theory

Question 1

The Cell Theory

Answer 1

1. All organisms composed of one or more cells
2. Cells are the smallest units of life
3. All cells come from pre-existing cells

Question 2

Evidence for cell theory

Answer 2

• Living cells can be visualized using microscopes since the 1600s
• No living organisms identified that are not made up of at least one cell
• Experimentation

Question 3

Exceptions to the Cell Theory

Answer 3

• skeletal muscle fiber cells and giant algae are large, polynucleated cells (not true individual cells)
• fungal hyphae are not always divided into indivdual cells/ they are actually multiple cells that share a continuous cytoplasm
• viruses are acellular, need host cell to care out functions of life

Question 4

7 functions of life

Answer 4

• Metabolism (chemical reactions)
• Reproduction (cell division/passing on hereditary molecules to offspring)
• Sensitivity/response (to stimuli/environment/adaptation)
• Homeostasis (internal balance/stability-temp/pH/ion levels etc.)
• Excretion (removal of the waste products of metabolism)
• Nutrition (obtaining chemical compounds for energy/growth)
• Growth (becoming larger/more complex)

Question 5

Why are cells small?

Answer 5

To maintain a high surface area to volume ratio. Cells want to maximize surface are to increase rate of material exchange and want to minimize volume for faster metabolic reaction rates

Question 6

What happens as cells grow?

Answer 6

As a cell grows the SA/V ratio decreases