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Pre-Lab Questions Hypothesize why a fungus would use spores as a mechanism for reproduction. Fungi reproduce by spores as spores can be dispersed away from the parent fungus to the substratum that has ample of moisture and nutrients to support the growth of mycelium. Spore dispersal reduces the possible competition among the progeny which would occur if all the new progeny also grows on the same substratum. Production of sexual spores also adds genetic variations to increase their survival rates. Also, spores can remain dormant during unfavorable conditions and germinate when enough moisture and nutrients are present. How might the environment influence whether a fungus reproduces sexually or asexually? Adverse environmental conditions stimulate sexual reproduction in fungi as it imparts genetic variations to the fungal population. These genetic variations allow the fungal species to survive the adverse conditions. Favorable growth conditions make the fungus to reproduce asexually. What characteristics of fungi are more plant-like? Animal-like? Plant-like features of fungus: Presence of cell wall around their cells. Inability to move from one place to another. Animal-like features of fungus: Heterotrophic mode of nutrition, absence of chlorophyll and plastids. Fungi cannot carry out photosynthesis and derive their nutrition from other sources. Experiment 1: Growing and Observing Zygomycota (Bread Mold) Slide Image Labeling To complete Step 8, use a pen or pencil to label the structures you identified in the Rhizopus slide images. 100x 400x 1000x Post-Lab Questions Include your hypothesis from Step 5 here. I believe that the wet piece of bread will experience more growth over time than the dry piece of bread. The bread will act as a sponge, soak up the water, and fungus and bacteria will start to grow over the course of a few days. Sketch the appearance of the bread mold. -14190903186804724310690200455295014048003381375131889545815256616704819710423440459111071900035147107092801228710148076022002755568951114425690245192135015664401562100157607012001501623695 What structures did you see in the bread mold? Different color of molds are present on bread mold. They are mostly yellowish white, rough surface, large oval or circular structures; some places would be very hard and dry as well. The dry location looks like the water has been sucked out. Why was it important to moisten the bread before sealing it in the bag? Moistening the bread will allow mold to grow quicker when kept in an incubated location. Water is required for the nutrition for fungi developed as the mold. Explain what type of control (positive or negative) the dry bread provided. The dry bread provides the negative results because the mold won't develop fast. There are no host cells in the bag, which would form a mold to develop so fast even though bread does mold. Is the bread mold reproducing sexually or asexually? How could you determine this? It reproduces both ways asexually and sexually. In asexual reproduction, the mold makes spores inside a sporangium. When the spores are ready to release and spread more mold, the sporangium breaks open and lets the spores float out. In sexual reproduction its hyphae touch the hyphae of another mycelium. When they fuse, they make round balls called zygospores. After some time, the zygospore forms another sporangium, which then makes spores. Genetic recombination takes place during the sexual process. What would you expect to find if you left the bread for six months? Both slices of bread will have grown mold and be completely covered in mold, but the wet slice will be worse. The wet slice will be almost dry from the fungus feeding off it. Experiment 2: Observing Ascomycota (Yeast) Post-Lab Questions Compare yeast to the Peziza slide. Identify at least one difference and one similarity. yeast cells can switch their morphology. F filamentous or unicellular. The yeast pseudohyphel switch is a model system for morphogenesis. m kar commonly a morphologic switch is associated with pathogenesis of C albicans and C neoformans. The hypha contains ascospores. Peziza upper surface the mature one is usually wrinkled near the center. A whitish and minutely fuzzy under surface, a round cup like shape when young and a flattened irregular shape when mature. the hymenium contains asci, ascospores, paraphysis. Similarity...In both slides we can see hyphae, ascus, ascospores. Difference...the ascospores of peziza are outside the ascus and ascospores of yeast are inside the ascus How many ascospores are in each ascus of the yeast? Eight. Typical a normal ascus contains eight ascospores. Are the ascospores of the Peziza inside or outside of the asci? outside the asci. The ascospores of peziza are forcibly discharged out from the ascus.