Elodea canadensis is a perennial hydrophyte, which is native to the majority of North America and was first recorded in about 1836 from the British Isles (Hackney, 1992). Young plants at first begin with a seedling stem and roots grow in mud at the underneath of water. More adventitious roots arise at intervals along the stem. The leaves are translucent, bright green, oblong, 1-4 mm broad and 6-17 mm long, borne in whorls of three round the stem (Rose, 2006). It lives completely submerged.
Blepharisma is a unicellular ciliate protists genus found in salt and fresh water (Miyake, Harumoto, Salvi, & Rivola, 1990). Blepharisma may be as tiny as 50μm in length or as big as 1 mm but normal size varies between 75 and 255μm. It has varying body shape within the genus.
Saccharomyces cerevisiae is a yeast species. It is probably the most important yeast, with the use in baking, brewing and winemaking since early times. Its cells are round to ovoid, with a diameter of 5–10 micrometers (Feldmann, 2010).
Micrococcus roseus is a gram positive bacterium that develops in the tetrad arrangement. The usual Micrococcus species habitat is soil, water, and skin. It obtains its name from the carotenoid pigment, which it releases. Its colonies are round, slightly convex, 1.0–1.5mm in size, smooth, and pink in color. Optimum growth temperatures vary between 25 and 35°C (Jagannadham, Chattopadhyay, & Shivaji, 1996)
Structurally, a human cheek cell is made up of cells like squamous and epithelial cells. Staining the cells with methylene blue stain makes the nucleus and cell membrane clearly visible under a microscope. The cells also miss some of the structures that are found in a plant cell such as chloroplast, cell wall and vacuole are absent. Lack of a rigid cell wall makes the cells to be flimsy and of irregular shapes unlike the plant cells which are rectangular in shape (Armstrong, 2012).
Euglena gracilis is a flagellated microorganism that is mainly found in freshwater environments. Euglena gracilis is characterized as a eukaryotic protist. However, the organism exhibits both animal and plant traits. It functions as a chemoheterotroph, as well as a photoautotroph. Euglena gracilis has the capability to grow in the dark and thus loses its chloroplast and using the heterotrophic metabolic strategy. It regains its chloroplast after being exposed to light. The green color seen in Euglena gracilis is as a result of the eat green algae that Euglena gracilis eat. They retain the algae in the body and use them to make food through photosynthesis (Moran, 2013).
The experiment aimed to use a Leica Galen III microscope to observe Elodea canadensis, human cheek cell, Blepharisma sp., Euglena gracilis, and yeast and bacteria cells.
The light green color observed in the leaf of Elodea canadensis was as a result of the low number of chloroplasts in the leaf cells. The length of the leaf was recorded to be 12mm which is within the range of 6-17mm that is in the literature (Rose, 2006). The rectangular shape of the cells is typical for plant cells due to the presence of a cell wall. Just like in a typical plant cell, the dark green chloroplasts in the cytoplasm were dispersed in an irregular manner. The length of the cells in the leaf was higher in some groups (114μm) than the average length (94μm).
The average length was, however, within the range for a typical plant cell of between 10-100μm. The average chloroplast size was 3.5μm, which was within the expected range of 3-10μm. Illuminating the cells for 5 minutes provided the cells with light necessary for photosynthesis. By the end of the 5 minutes, the cells had produced nutrients for the cell to use, and cyclosis process was necessary to deliver the produced nutrients and other materials to all cell parts (Bulychev & Dodonova, 2011).
Staining the human cheek epithelial cells revealed the round shape of the cells, nucleus and the cell membrane. The cells were not tightly packed as the cells are dependent on the environment surrounding them. The cells were surrounded by a plasma membrane and had an irregular shape. The shape was due to lack of a rigid cell wall as found in a plant cell (Armstrong, 2012). The diameter of the cheek cell was recorded as 24μm, which is within the known diameter of a human cell (10 to 50μm). The nucleus was located at the center just like in a typical animal cell and the darker blue color shown by the nucleus was due to the densely packed nucleus content.
The length of Blepharisma sp. was recorded to be 223μm, with the mean for all the groups being 206.4μm. The length was within normal size range of between 75 and 255μm (Fernandes, Dias, Senra, Soares, & da Silva Neto, 2013). Just like in a normal cell, the cytoplasm was granular in appearance and had several large food vacuoles, a micronucleus, a macronucleus, and a large central vacuole. The numerous cilia that were on the exterior of the cell are used for locomotion. Protoslo reduces the viscosity of the media in which the specimen moves. The observed specimen still moved with a smooth, gliding motion even after the addition of Protoslo.
The Euglena gracilis feeds on algae which provide the numerous chloroplasts contained in the cytoplasm. The study indicated the shape of the Euglena gracilis to be cylindrical as reported in the literature (Moran, 2013). The experiment also confirmed the presence of a dark red photoreceptor in the cytoplasm. This is the eyespot that is used by the Euglena gracilis to locate light to be used by the chloroplasts to make food. The specimen moved with a jerky, non-uniform motion through a flagellum that is embedded in the pellicle (Moran, 2013). The nucleus was located just past the midpoint of the organism. The length was determined to be 59μm and fell within the typical length range of between 20μm – 100μm (Gruenberger, Ritter, Aumayr, Stachelberger, & Gebeshuber, 2013).
The lengths of the yeast cells (5.5μm) and bacteria (1.1μm) were within the range of 5-10μm and 1.0–1.5μm respectively. Brownian motion observed for both types of cell occurred as the methylene blue moved from a high concentrated area to a low concentrated area through diffusion. The large nucleus and vacuole distinguished the yeast cell from the bacteria cell. The features that were characteristic in a bacteria cell were the cell wall and cytoplasm.
Armstrong, W. (2012). Physical Properties & Structure of Cells. Retrieved September 29, 2013, from http://waynesword.palomar.edu/lmexer1.htm#cheek
Bulychev, A. A., & Dodonova, S. O. (2011). Effects of cyclosis on chloroplast–cytoplasm interactions revealed with localized lighting in characean cells at rest and after electrical excitation. Biochimica et Biophysica Acta (BBA)-Bioenergetics, 1807(9), 1221-1230.
Feldmann, H. (2010). Yeast. Molecular and Cell Biology. Hoboken, New Jersey: Wiley-Blackwell.
Fernandes, N. M., Dias, R. J., Senra, M. V., Soares, C. A., & da Silva Neto, I. D. (2013). Morphology and 18S rDNA gene sequence of Blepharisma sinuosum Sawaya, 1940 (Ciliophora: Heterotrichea) from Brazil. European Journal of Protistology.
Gruenberger, C., Ritter, R., Aumayr, F., Stachelberger, H., & Gebeshuber, I. C. (2013). Biophysics of green algae: Euglena gracilis investigated by atomic force microscopy. Retrieved September 29, 2013, from http://www.iap.tuwien.ac.at/~gebeshuber/ALGAE_OEPG.PDF
Hackney, P. (1992). Stewart and Corry's Flora of the North-east of Ireland. Institute of Irish Studies and The Queen's University of Belfast.
Jagannadham, M., Chattopadhyay, M. K., & Shivaji, S. (1996). The major carotenoid pigment of a psychrotrophic Micrococcus roseus strain: fluorescence properties of the pigment and its binding to membranes. Biochemical and Biophysical Research Communication, 220(3), 724–728.
Miyake, A., Harumoto, T., Salvi, B., & Rivola, V. (1990). Defensive function of pigment granules in Blepharisma japonicum. European journal of protistology, 25(4), 310-315.
Moran, M. (2013). Euglena. Retrieved September 29, 2013, from http://www.fcps.edu/islandcreekes/ecology/euglena.htm
Rose, F. (2006). The Wild Flower Key. London: Frederick Warne & Co.