Algea
Algae are simple water plants. They contain chlorophyll and photosynthesize (retain water, light and carbon dioxide to produce food and oxygen). They are eukaryotic having a full fledged nucleus, and contrary to prokaryotic cells, they have cell walls usually composed of cellulose. Algae come in different colours, shapes and sizes (10-25 Um to 200m); some are unicellular, or found in simple to complex colony style endeavors and even in multicellular structures. Some are mobile; propelled by their flagella, and some have specialized cells called holdfast to get a grip on things. Reproduction can be both asexual and sexual for these simple, yet abundant plants. Algae are amongst the most important food producing groups in the world, and are by far responsible for over 90% of the oxygen in this world. They are found in just about any type of environment though they are dependant on light (photosynthetic) and water for most of their basic needs. The most important factor of survival for algae is their immediate habitat. Since algae are photosynthetic they cannot survive without light, thus they must live in the presence of light. Because algae are simple plants and lack the complexity of having a thick and vascular assembly, they ar
A fourth type of sexual reproduction, seen in the Ulva, is called alternation of generations where the offspring are like the grandparents and not the parents. Alternation of generations has two multicellular stages, one of which produces gametes and one of which produces spores. So the multicellular gamete-producing generation, or the Gametophyte, alternates with the multicellular spore-producing generation, or the Sporophyte. First we have the Gametophyte which develops into a gametangium, which releases gametes, the gametes fertilize and form a zygote, and the zygote develops into a sporophyte. The Sporophyte develops into a sporangium, that develops into a spore mother cell which undergoes meiosis to produce a meiospore that develops into a Gametophyte. To maintain their position, most algae use specialized cells called holdfast cells. These cells do not partake in reproduction or photosynthesis processes, they simply grab hold of ground or a rock and they hold the rest of the plant there. Chlamydomonas does not have this special cell it has two flagellae instead. It can use the flagella to swim around to where it can receive needed materials or light energy for photosynthesis. The other flagellated algae are the colonies which are composed of numerous unicellular organisms similar to Chlamydomonas. Some algae, like Fucus and other brown algae, use air bladders to lift themselves up towards surface. The fifth type of sexual reproduction found in algae is seen in the marine Fucus. It is similar to that of oogamy but a bit more complex. The Sporophyte produces two types of sporangia, a microsporangium (small male), and a mega sporangium (large female). The sporangia undergo meiosis and produce a microspore (male) and a megaspore (female) respectively. The microspore develops into a microgametophyte and the megaspore into a mega gametophyte. The microgametophyte develops an Antheridium which releases sperm, and the mega gametophyte develops into an Oogonium which releases eggs. The sperm fertilizes the egg to form a zygote which will develop once more into a sporophyte. e constantly in need of water for structural support and to prevent them from drying out. Most Phylum Chlorophyta algae (green algae) live in fresh water: places such as lakes, ponds and streams. Chlamydomonas, a genus of green algae, are common in ditches, pools, and other bodies of s
Some common words found in the essay are:
Chlamydomonas Ulothrix, CO2 H2O, Sporophyte Gametophyte, , Phylum Phaeophyta, Oedogonium Spirogyra, Phylum Chlorophyta, Ulothrix Spirogyra, Oedogonium Ulothrix, Pleodorina Volvox, green algae, type sexual reproduction, sexual reproduction, vegetative cells, type sexual, algae simple, asexual reproduction, brown algae, raw materials, cells algae, type asexual, type asexual reproduction, standing fresh water, composed vegetative cells, zoospores develop adults,
Approximate Word count = 1602
Approximate Pages = 6 (250 words per page double spaced)
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