A long 350 million years ago, life on land was unsuitable for plants to live on with the little to no supply of oxygen and the harmful ultraviolet rays of the scorching sun. This lead to life beginning in the ocean where scientists have traced back to an ancestral bryophyte (also known as freshwater green algae) that has, over time, developed a key process of making food by using the energy from sunlight to convert carbon dioxide and water into by glucose and oxygen. The plant life history also involves the "alternations of generations" that allows a plant to undergo meiotic/mitotic phases between the sporophyte(diploid) and gametophyte(haploid) generation. In leaves, gas exchange occurs through little pores called the stomata which are present in the sporophyte generation. These small openings are light sensitive, so they are most commonly located on the bottom of leaves to prevent dehydration. The stomata usually open in the morning, and close in the night in C3 and C4 plants. Although, many plants species are different when you compare their stomata orientation. One of the two major groups of flowering plants(angiosperms) are monocots, which include palms. These trees have adapted to harsh, dry environments. The deep roots of a palm tree allow it to reach far below the soil and obtain the necessary water and minerals stored at the bottom, and to help it grow. Its giant sized leaves allows for maximum sunlight exposure and its waxy surface cuticle of its leaves prevent the large loss of water from leaf due to transpiration.
For the lab, I observed six leaves collected from six different plants growing sporadically around the school campus. Using clear tape, sticking it to the bottom of each leaf, applying pressure, and carefully peeling the tape off for an imprint of the leaf. I stuck the tape onto a glass slide and placed it under the microscope and observed the cells. Adjusting the magnification down 1000x, it is noticeable that the stomata were open...
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