The Differences in the Number of Stomata amongst Three Different Life Stages of Leaves Introduction
Stomata control a tradeoff for the plant: they allow carbon dioxide in, but they also let precious water escape. A plant that could get enough carbon dioxide with fewer stomata would have an advantage since it would be better able to conserve its water. Levels of carbon dioxide in Earth's atmosphere change over time — so at times when the atmosphere is carbon-dioxide-rich, plants can get away with having fewer stomata since each individual stoma will be able to bring in more carbon dioxide. During those high-carbon-dioxide times, plants with fewer stomata will have an advantage and will be common. On the other hand, when carbon dioxide levels are low, plants need many stomata in order to scrape together enough carbon dioxide to survive. During low-carbon-dioxide times, plants with more stomata will have an advantage and will be common. (Understanding Evolution) Therefore, the question to be tested will be if you count the number of stomata of the same species of leaf at different stages of life will the number of stomata be different? My hypothesis is if we count the number of leaf stomata at three different stages of life then the number of stomata will be less as the leaf gets older because the leaf is dying. (Understanding Evolution) Procedure
Approximately three leaves of the where gathered to use in this experiment. Each leaf was at a different stage of life: alive, dying, and dead. A thin cast of a tiny part of the surface of the underside of each leaf was created using NYC clear nail polish. The imprint of each leaf’s underside was viewed one at a time under a light microscope using the cast, which was carefully removed from each leaf with a piece of packing tape. The stomata were completely visible and were able to be counted under the lowest view setting of 100x. The stomata of each leaf were observed and counted four times. When viewing the stomata in...
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