Stomata Lab Report
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 since it was early morning to collect any moisture, sunlight, and oxygen in the air. Thus, narrowing down the plants to be either C3 or C4 plants since CAM plants only open their stomata at night. Plant species 1 had mesophyll cells surrounding the stoma were which were formed in parallel layers, similar to the visual on page 128, leading to conclude that it was C3. Plant species 2 had mesophyll cells that were again, arranged in parallel layers so another
C3 plant. Plant species 3 is also a C3. Plant species number 4 is also the same. Oh, but plant species 5 is differently arranged, the mesophyll cells are more concentric around the bundle sheath cells, therefore, it being a C4 plant. Plant species 6 has the same mesophyll cell pattern as plant species 5 so it is also a C4 plant. When I got a sample of a palm tree leaf imprint, the mesophyll cells are well-formed and arranged in parallel layers just like Plant species 1, 2, and 3 so a palm tree is a C3 plant.
In conclusion, most of the leaves were similar but when observed more closely their differences are more obvious. Some plants had more stomata than the other although they were found on the same part of the leaves. This is most likely due to the fact that each plant has a specific amount of nutrients they need to be well nourished in order to survive. When you compare normal leaves to an actual plant like the palm tree that adapted to Florida’s hot environment, there was significantly more stomata all around the not-so broad leaves.