Stomata density denzel,breana


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Stomata density denzel,breana

  1. 1. Stomata Density By: Breana Hull Denzel Drennon
  2. 2. What Are Stomata? 1 <ul><li>A microscopic spore in the epidermis of plants </li></ul><ul><li>surrounded by guard cells </li></ul><ul><li>In leaves and stems of a plant </li></ul><ul><li>allows gas exchange between the environment and the interior of the plant </li></ul><ul><li>Surrounded by guard cells which control the opening and closing of the stomata </li></ul>
  3. 3. What Are Stomata Cont. 1 <ul><li>There are three cues for Stomatal opening: </li></ul><ul><li>Depletion of carbon dioxide within the plant </li></ul><ul><li>Light at dawn triggers the guard cells </li></ul><ul><li>The internal clock of the guard cells </li></ul>
  4. 4. Guard Cells 1 <ul><li>Guard cells become turgid when swollen with water causing an opening in the stoma </li></ul><ul><li>When they lose water they become flaccid causing the stoma to close </li></ul><ul><li>Water is stabilized in and out of the guard cells as potassium ions are transported across the plasma membrane, regulating the amount of water and ions taken in. </li></ul>
  5. 5. What do Stomata do? 1 <ul><li>Main avenues of TRANSPIRATION: </li></ul><ul><ul><li>Transpiration is the evaporative loss of water through a plants leaves. </li></ul></ul><ul><li>Balance the requirement for water conservation for photosynthesis </li></ul><ul><li>Open during the day and close at night to prevent water loss </li></ul><ul><ul><li>Especially in low water and high temperature conditions </li></ul></ul><ul><li>Regulate the carbon dioxide intake and oxygen output for photosynthesis. </li></ul><ul><li>Provides gas exchange for the plant </li></ul>
  6. 6. Why is it interesting to study stomata? 1 <ul><li>95% of a plant’s water loss is through these small pores. </li></ul><ul><li>An internal clock in the guard cells open the stomata at dawn even if plant is in the dark. </li></ul>
  7. 7. Hypothesis stomata density in leaves directly exposed to the sun will be greater then those in the shade In this environment the southern faced leaves are directly exposed to sunlight, where the northern faced leaves are low to the ground with less sunlight exposure.
  8. 8. We believe this has an effect because 4 : <ul><li>Increase gas exchange </li></ul><ul><li>therefore more water released </li></ul><ul><li>lowering plant temperature in times of high sunlit conditions. </li></ul>
  9. 9. On the other hand… <ul><li>If these plants were put under conditions with limited water, there would be hypothesized to have less stomata in leaves of the sun. 4 </li></ul>
  10. 10. Holly <ul><li>NORTH (shaded) </li></ul><ul><li>Found closest to the ground, under the bush </li></ul><ul><li>Smaller leaves </li></ul><ul><li>Lighter yellow/green </li></ul>
  11. 11. Holly <ul><li>SOUTH (sun) </li></ul><ul><li>Found on top of bush, fully exposed </li></ul><ul><li>Bigger leaves </li></ul><ul><li>Dark green </li></ul>
  12. 12. Methods <ul><li>Gather leaf samples from site; 12 leaves from shaded, north facing AND 12 leaves from direct sun, south facing </li></ul><ul><li>Paint underside of leaves with clear nail polish </li></ul><ul><li>Place clear scotch tape on underside of leaf once dry </li></ul><ul><li>Place tape on slide and label </li></ul><ul><li>Under microscope, count number of stomata for 3 fields of view on all 24 leaves </li></ul><ul><li>Measure field of view in millimeters under 400 x </li></ul>
  13. 13. Results <ul><li>The stomata density in leaves of the sun are greater than those in the shade </li></ul><ul><li>YES! </li></ul><ul><li>We accept our hypothesis </li></ul>
  14. 14. 251.92
  15. 15. Conclusion Looking at the t Critical and t Stat , we confirm that there is a significant difference between stomata density in leaves of the shade and sun areas Looking at the Probability we can assure that we are 100% sure of our conclusion Statistics Sun Shade Mean 251.92 186.50 Variance 1202.34 452.27 Standard Deviation 34.67 21.27 t Stat 5.57108 t Critical one-tail 1.73406 P(T<=t) one-tail 1.372 x 10 -5
  16. 16. Future Study <ul><li>The shade of the leaf compared to the stomata density </li></ul><ul><li>Hypothesis: </li></ul><ul><li>Darker leaves have more stomata then lighter </li></ul><ul><li>Because: </li></ul><ul><li>The darker color of leaves attracts sunlight </li></ul>
  17. 17. References: <ul><li>Campbell, Neil. 2010. Biology. Edition 8. Pearson Education, Inc. </li></ul><ul><li>http:// . “February 16, 2011” </li></ul><ul><li>http:// . “February 16, 2011” </li></ul><ul><li>Bruce W. Grant, Itzick Vatnick, and the Ecological Society of America. 2004.Environmental Correlates of Stomata Density. TIEE. http:// . “ February16, 2011 ” </li></ul>