Monday, July 22, 2019

Ceratopteris Fern Growth and Analysis Essay Example for Free

Ceratopteris Fern Growth and Analysis Essay I: Abstract Observing the effects of ammonium nitrate has on the germination days of C-Fern gametophytes by constructing an experiment with two spore-sown petri dishes, one control and one treatment – a normal nutrient-rich agar petri dish and an ammonium nitrate-containing petri dish respectively. The two petri dishes were each inoculated with three drops of spore suspension by a pipet, then spores were spread by a sterilized-bent paper clip to allow even distribution of spores. Gametophyte germination occurred approximately two weeks after inoculation for the control, and gametophyte germination occurred approximately three weeks after inoculation for the treatment; thus possibly suggesting ammonium nitrate worked to hinder the mitotic cell division in the haploid gametophyte. II: Introduction C-Fern begins with a haploid spore known as the spore imbibition (Hickok, Warne 2009), then after 3 to 4 days the spore will develop into a gametophyte via mitosis after germination. This is a photoautotrophic process. The gametophyte will then undergo differentiation (Hickok, Warne 2009), to form the antheridium and the archegonium after 6 to 8 days (Hickok, Warne 2009). Following the gametophyte displaying its hermaphrodite form, sexual maturity allows cross-fertilization to occur between the sperm from antheridium and the egg from archegonium. After one sperm fertilizes the egg, a zygote forms, thus forming a diploid cell (Hoshizaki 2001). The formation of the zygote exemplifies sporophytes’ alternation of generations via the diploid cell completing mitosis and meiosis yet still retaining a full set of genetic material. In other words, alternation of generation refers to going from a multicellular diploid form to a multicellular haploid form. (Hickok, Warne 2009). The fertilized egg develops into a sporophyte by mitosis to form a microscopic young fern (embryo), which is a gametophyte under the reproductive leaves called sporangia. Note that sporophytes are diploid and gametophytes are haploid. When the sporophyte reaches maturity, it releases spores via meiosis, then the spores will undergo mitosis, thus forming gametophytes, and the life cycle continues (Brooker 2011). Figure 1 is a pictorial depiction of the life cycle of a fern. [pic] Figure 1: The life cycle of a fern. [1] This experiment aims to discover the germination time of C-Fern under a controlled condition and a treatment condition. Experimenting if the treatment of ammonium nitrate will allow faster germination of the C-Fern. Some data shows that ammonium nitrate possibly functions as a fertilizer for many species of plants, however, not all plants will reap the benefits of ammonium nitrate (Aderkas 1984). [2] The null hypothesis of this experiment is that the ammonium nitrate will not hinder the rate of germination of the C-Fern, thus the data obtained from the control will not have a statistical difference from the data obtained from the treatment. III: Methods Two 60 mm petri dishes were prepared. One labeled â€Å"C† for control, another labeled â€Å"T† for treatment. The control contained a layer of agar and the treatment contained agar and ammonium nitrate. Petri dish for control was inoculated with three drops of C-Fern spore suspension via a pipette, and petri dish for treatment was inoculated three drops of C-Fern spore suspension via the same pipette. A Bunsen burner was used to sterilize a bent â€Å"T† shaped paper clip, the paper clip was used to spread the spore suspension in the petri dish for control. The same paper clip was sterilized again by a 70% ethanol solution and was used to spread spore suspension in treatment petri dish. Two petri dishes were each covered with a lid and now considered culture trays, culture trays then were transported to a climate controlled light dome for optimal growth. Light dome maintained a full spectrum of light 24/7 with temperature in the range of 28 to 30 degrees Celsiu s. Observations were made on every Friday at approximately 3:10 pm for the next 3 weeks. Spores were sown in the week of September 10th and no observations were made. First observation was made in the week of September 17th, Friday 3:08 pm, the control displayed some growth with flagella-like hair, however, no germination was observed. The treatment did not display any signs of growth, only air-like bubbles were observed. Second observation was made in the week of September 24th, Friday 3:10 pm, the control displayed germination, gametophytes were visible under the microscope, however, hermaphrodites were not significantly observed. The treatment still does not display signs of germination, only small green spores were observed under the microscope. Last observation was made in the week of October 1st, Friday 3:05 pm, the control displayed significant signs of growth, it appeared that fertilization took place and an embryo was in development. The treatment only displayed minimal germination, however, some spores appeared to be infested with fungus.

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