2.3 Cell and Organism Size
in AP Biology
The surface-to-volume ratio is an important parameter affecting cell size and shape.
To Think About:
Why are cells typically small? How is the surface area to volume ratio calculated? What are some examples of structural modifications of cells that increase surface area? How does the surface area to volume ratio affect the rate of heat exchange with the environment? How are specialized structures and strategies used by cells and organisms for the efficient exchange of molecules with the environment?
Watch: AP Daily Video- Cell Size Video One and Two
Answer the Following Questions:
- Why are smaller cells more efficient at exchanging materials with their environments?
- What is the surface area to volume ration for a 1 cm cube? For a 2 cm cube? For a 3 cm cube?
- As cells get larger their surface area to volume ratios____________________.
- As cells increase in volume, their relative surface area to volume ratio____________________but their demand for resources____________________.
- Describe an adaptation that plants have to increase their surface area to volume ratio.
- Describe an adaptation that the small intestine has to increase its surface area to volume ration.
- How does the surface area to volume ratio affect the rate of heat exchange in elephants? What adaptation do elephants have to deal with this?
Supplementary Resources:
- Bozeman Science: Diffusion and Osmosis
- Bozeman Science: Diffusion Experiments
- Bozeman Science: Osmosis Lab Walkthrough
- Bozeman Science: Osmosis Demo
- BOGObiology: Hypertonic, hypotonic and isotonic solutions
