INTRODUCTION
Chlamydomonas reinhardtii is a unicellular, eukaryotic green algae that is commonly found throughout the world. This photosynthetic organism possesses two flagella that serve as the basis of its motility. Not only is this organism easily accessible, but it is a model organism for many areas of study (Rochaix et al, Silflow and Lefebvre 2001) including photosynthesis, respiration, flagella, circadian rhythm, cell to cell recognition and even heavy metal homeostasis and tolerance (M. Hanikenne). The flagella of C. reinhardtii are easily visible and are remarkably similar to other mammalian microtubule structures (Silflow and Lefebvre 2001). This allows experimental studies to occur that are able to aid in the understanding of human disease related to the dysfunction of microtubule structures within the human body. Since these organisms are capable of sustaining life in absence of their flagella, they become a model organism for studying movement, regeneration and mutational defects. The flagella are easily removed without damaging the cell and make flagellar protein analysis a simpler process. Genetic analysis of mutant strains is easily accessible because of the complete sequencing of its genomes (Lefebvre and Silflow 1999).
Although flagellum does not have a life-sustaining role in this organism, it is still very beneficial throughout its lifecycle. Like all chlorophyll producing plants, C. reinhardtii requires light to support its cellular functions. In order to enhance its ability to receive the ideal quantity, it is able to sense light with an eyespot and use these signals to control the beating of the flagella (Witman GB 1993). C. reinhardtii is able to propel itself forward by the opposite and simultaneous mo...
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5. Rochaix JD, Goldschmidt-Clermont M, Merchant S. 1998. The molecular biology of chloroplasts and mitochondria in Chlamydomonas. Dordrecht, The Netherlands: Kluwer Academic Publishers.
6. Silflow CD, Lefebvre PA. 2001. Assembly and motility of eukaryotic cilia and flagella. Lessons from Chlamydomonas reinhardtii. Plant Physiology 127: 1500–1507.
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The Organism & it’s Life Cycle: Chlamydia are obligate intracellular parasites, and are among the smallest living organisms. There are two stages in the life of Chlamydia: elementary bodies and reticulate bodies. Another feature of Chlamydia is that they are unable to synthesize their own energy (ATP) and are completely dependent on their host for energy. The organism is in the elementary stage of its life when it encounters its host and is taken up by phagocytosis. It prevents the fusion of the phagosome and lysosome; this is what normally kills pathogens. Once the phagolysosome formation is stopped, the bacteria secrete glycogen and transform into the reticulate body. Reticulate bodies obtain their energy by sending forth “straw-like” structures into the host cell cytoplasm, and they divide by binary fission. Each phagolysosome produces about 100-1000 reticulate bodies.
N fowleri has three stages of their cycle. In the amoeboid trophozoite stage, they are infectious and measure 10-35 µm long. The trophozoite transforms to a non-feeding flagellate when food sources are limited. Flagellates are motile and measure 10-20 µm in length. The amoeba or flagellate will form a cyst, the dormant stage, if the environment is too cold and not conducive to continued feeding and growth. When the organism is in the cyst stage, it has a single layered wall and only one nucleus. The cyst measures 7-1...
Though these morphological changes have been known for some time, very little is known about the mechanisms underlying them. The processes that govern cell cycle regulation are of great interest to researchers, as aberrations like improper chromosome segregation and nonfunctional microtubule assembly can result in apoptosis or, if the cell doesn’t undergo apoptosis, cancer. Most evidence surrounding cell cycle regulation comes from studies on embryonic development of amphibians. Amphibian eggs contain many of the proteins required to carry out mitosis, but can only enter mitosis after fertilization. In addition to these proteins, the eggs contain a v...
Chloroplasts are and organelle that contains chlorophyll, and is the place where photosynthesis takes place. In a basketball stadium, the concession stands are like chloroplasts. The concession stands is like chloroplast because it makes food for everyone at the game. This is how chloroplasts and the concession stands are alike because they both make food.
One can almost feel the searing penetration of Lewis Thomas’ analytical eye as it descends the narrow barrel of the microscope and explodes onto a scene of vigorous, animated, interactive little cells—cells inescapably engrossed in relaying messages to one another with every bump and bounce; with every brush of the elbow, lick of the stamp, and click of the mouse…
Devlin, Robert M. and Allen V. Barker. Photosynthesis. New York, Van Nostrand Reinhold Company, 1971.
Recreating the evolutionary history of dinoflagellates has been challenging as they possess a known ability to transform from noncyst – to cyst – forming strategies (unreferenced/Wikipedia). The dinoflagellate nucleus lacks histones, nucleosomes and maintains continually condensed chromosomes during mitosis (Dodge 1966), making their classification difficult (Hackett et al 2004). Though being classified as eukaryotes, the dinoflagellate nuclei are not characteristically eukaryotic (Dodge 1966). However, typical eukaryotic organelles, such as Golgi bodies, mitochondria and chloroplasts are present in dinoflagellates (Morrill et al 1983). Since dinoflagellate nuclei possess intermediate characteristics between the coiled DNA areas of prokaryotic bacteria and the well-defined eukaryotic nucleus it was termed ‘mesokaryotic’ by Dodge (1966).
Cain, M. L., Urry, L. A., & Reece, J. B. (2010). Campbell Biology. Benjamin Cummings.
The cytoskeleton is a highly dynamic intracellular platform constituted by a three-dimensional network of proteins responsible for key cellular roles as structure and shape, cell growth and development, and offering to the cell with "motility" that being the ability of the entire cell to move and for material to be moved within the cell in a regulated fashion (vesicle trafficking)’, (intechopen 2017). The cytoskeleton is made of microtubules, filaments, and fibres - they give the cytoplasm physical support. Michael Kent, (2000) describes the cytoskeleton as the ‘internal framework’, this is because it shapes the cell and provides support to cellular extensions – such as microvilli. In some cells it is used in intracellular transport. Since the shape of the cell is constantly changing, the microtubules will also change, they will readjust and reassemble to fit the needs of the cell.
Sperry, R. W. (1963, October 15). Chemoaffinity in the Orderly Growth of Nerve Fiber Patterns and Connection. Natioanl Academy of Science, 50(4), 703-710.
In this cell though, the nucleus was not present. The plant cells and animal cells were very different. In the plant cells there was motion of cell parts but in the animal cells there was no motion. Also, the nucleus and chloroplast of the plant cell were towards the outside of the cell because the chloroplast can receive sunlight better on the outside of the cell than on the inside. In the animal cells though, the nucleus and cell organelles, were towards the middle of the cell.
This organelle is the site of photosynthesis in plants and other organisms. In the structure, the chloroplasts has a double membrane, the outer membrane has a continuous boundary. This organelle can be found in a vast group of organelles called the plastid, chloroplasts are usually found in many plant cells but never in animal cells. Chloroplasts organelles are large; they are 4-10um long and 2-3um wide. They are very important to plants because chloroplasts are what plants use to create food from sunlight. Chloroplasts are not found in humans.
Wilkie, I.C. "Autotomy as a Prelude to Regeneration in Echinoderms." Microscopy Research and Technique 55.6 (2001): 369-96. Print.
Diatoms have a unique characteristic. They live in an outer cell wall, or a frustrule made of silica. This frustrule is not just for the physical appearance, it provides protection and even structure. On the cell wall, there are spikes, spines and pores which allow diatoms to be classified into different classes, the centric (Centrobacillariophyceae) and the pennate (...
A number of organs have the intrinsic ability to regenerate, a distinctive feature that varies among organisms. Organ regeneration is a process not fully yet understood however when its underlyning mechanism are unreveled, it holds tremendous therapeutic potential for humans. [28]