Friday, 22 February 2013

2.55 explain how the rate of transpiration is affected by changes in humidity, wind speed, temperature and light intensity

Humidity
Increased humidity decreases transpiration. This is because high water content outside the leaf will mean there is little difference in concentration, so the water will not be able to move- as it naturally does- from an area of high concontrartion to an area of low concentration.
Wind speed
Increased wind speed will increase transpiration. Because if the wind blows away the water vapour being produced their will be a greater difference in water concentration, meaning water will be able to continue leaving the leaf.
Temperature
Increased temperature increases transpiration, as increased heat makes evaporating easyer.
Light intensity
Increased light intensity increases transpiration, as more heat is absorbed by the leaf meaning more water will be evaporated, also there is more photosynthesis meaning more water is being transported through the leaf (so more will need to leave the leaf.)

9 comments:

  1. when you say "water moves from an area of low concentration to high concentration" when discussing the effects of humidity, possibly make it clearer that you are referring to the concentration of other substances, not of water itself (which moves down a concentration of water gradient)

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    1. Think she just got them the wrong way round

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    2. Also im in your science set (5E)

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  2. Light causes stomata to open in the leaves allowing water to escape also rather than saying that evaporating is easier it might be better to say that the rate of evaporation is increased with increased temperatures

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  3. This comment has been removed by the author.

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  4. Clearly she didn't get an A* in english lol.

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  5. The Biology Syllabus has changed.... New Syllabus Blog:

    http://igcse-biology-2017.blogspot.hk

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  6. more at

    http://igcse-biology-notes.blogspot.hk/2017/06/255-explain-how-rate-of-transpiration.html

    ReplyDelete