Topic 2.3 - Cell Size 𖦹⋆｡°✩ Flashcards
what is more difficult as cell size increases
moving materials (nutrients, waste) in and out of cells gets more difficult the larger a cell is
✩ PRACTICE SURFACE AREA:VOLUME RATIO QUESTIONS✩
what is the relationship between cell size and SA:V ratio
༻ smaller cells have a higher SA:V ratio
༻ more efficient exchange of materials with the environment
what happens as cells increase in volume
as cells increase in volume, the SA decreases making it difficult for larger cells to meet the demand for internal resources and remove waste sufficiently
… demand for internal resources increases
what can these limitations result in
can restrict cell size and shape
why are complex structures necessary
necessary to adequately exchange materials with the environment
… the SA of the plasma membrane must be large enough to adequately exchange materials
what does membrane folding increase. provide an example
membrane folding increases SA.
༻ ex. root hairs on the surface of plant roots
༻ ex. the outer lining of the small intestine
what can an increase in size lead to
increase in size leads to a decrease in SA:V ratio, affecting properties like rate of heat exchange with the environment
༻ ex. flat elephant ears allow elephant to dissipate more thermal energy as blood flows closer to the surface
what have organisms evolved to obtain nutrients and eliminate waste
evolved highly efficient strategies
what is an example of these strategies
cells and organisms use specialized exchange surfaces
༻ ex. stomatal openings in leaves obtain molecules from and release molecules into the surrounding environment. when stomata open, CO2 enters and H2O flows through the leaf
✩REVIEW LAST QUESTION FROM VIDEO LESSON✩
