Friday, November 18, 2011

Would u expect the leaf of a desert cactus or the leaf of a water lily to have more stomata???

need to know about the stomata, the function for the plant, or/and how the stomata function(the role)of the plant

Would u expect the leaf of a desert cactus or the leaf of a water lily to have more stomata???
The water lilly would have a higher number of stoma. The cactus would have fewer because it needs to lose less H2O through evaporation, and the water lilly would have a larger amount even though it is in H2O because it needs more air so it won't drown.
Reply:the stomata is actually an opening formed by 2 guard cells that are kidney/bean shaped and are supported by many epidermal cells.


these guard cells have a property of their outer walls being thicker than their inner walls, and also that they actively photosynthesise to release products that regulate their turgor pressure.


now when transpiration has to take place these guard cells swell up by taking in water and their inner walls being thinner don't curve as much as the outer walls do...hence they form an opening throught which water escapes as vapours.





now since a cactus is already having less water, hence it'll try avoiding this water loss...hence relatively the no. of stomata will be lesser, also their epidermis is covered by a thick waxy cuticle that prevents water loss...in comparison a water lily...has plenty of water and needs to lose them efficiently to survive, hence it has more no. of stomata and mainly on the upper leaf surface that remains exposed as well as on the stem parts.





apart from maintaining the water balance of a plant...the transpiration caused due to opening of a stomata is also responsible for the uptake of water from the roots by tall trees...this is called TRANSPIRATIONAL PULL theory

Dog Teeth

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