Solved by a verified expert:BIOL 1020FUNGI:CHARACTERISTICS & CLASSIFICATIONOBJECTIVESDiscuss why fungi are not classified with plants.Understand how fungi are fundamentally different from other living organisms.Identify the distinguishing features of the four major groups of fungi.Explain the role of fungi as decomposers.Formulate and test a hypothesis that investigates the environmental conditionsnecessary for mold spore germination and growth.INTRODUCTIONThere are four phyla traditionally recognized as belonging to the Kingdom Fungi that youwill learn about in this course. These phyla are the Chytridiomycota (chytrids), Zygomycota(zygomycetes or sporangium fungi), Ascomycota (ascomycetes or sac fungi), andBasidiomycota (basidiomycetes or club fungi). Fungi, like plants and animals, belong to thedomain Eukarya. Fungi are heterotrophs, but unlike animals, they secrete digestiveenzymes externally and then absorb the nutrients. Fungi are also very diverse. There areunicellular and multicellular fungi. Also, some fungi reproduce sexually while othersreproduce asexually. Furthermore, there are fungi that are saprophytic (eat deadorganisms), while others are parasitic. The saprophytic fungi, along with saprophyticbacteria, are essential decomposers; we rely on saprobes to break down dead organicmatter and recycle nitrogen and other inorganic nutrients back into the environment.Some fungi form mutualistic relationships with a photosynthetic partner – either algae orcyanobacteria – to form lichen. Species of this type of fungus are mainly found in thephylum Ascomycota and a few are also found in the phylum Basidiomycota. Other fungiform mutualistic relationships with plant roots as mycorrhizae. The fungi provide plant rootswith phosphate ions and other minerals from the soil and the plant roots provide carbonfrom photosynthesis to the fungi. Most mycorrhizae are from the phylum Basidiomycotaand a few are from the phylum Zygomycota as well as the phylum Ascomycota.Fungi have hyphae, which consist of a network of filaments that are composed of tubularcell walls that surround the plasma membrane. The hyphae are like branches on a tree.Fungi also have mycelium, which consist of an interwoven mass of hyphae that increasesthe surface area for the absorption of nutrients from the soil. Mycelium is like the roots of aplant because they extend outward into the soil.1 Fungi: Characteristics & ClassificationBIOL 1020LABORATORY ACTIVITIESEXERCISE 1: FUNGAL BASICSPROTOCOL:This activity is designed to assess your basic knowledge of fungi. You may use theintroduction to this lab, your text, or other appropriate resources to answer the followingquestions. Be sure your answers are in your own words and not copied directly from yoursource material.QUESTIONS:1.Fungi are evolutionarily more closely related to animals than they are to plants. Listand explain three pieces of evidence that support this statement.2.Like animals, fungi are heterotrophs; however, their means of acquiring nutrients isquite different. Explain.3.Discuss how the sexual spores of chytrids, zygomycetes, ascomycetes, andbasidiomycetes differ from each other.4.How would the natural environment be altered if there were no saprophytic fungi orbacteria?5.Provide one specific example that illustrates how fungi can be harmful to humans.Your answer should identify a specific fungus and talk about the harm that it causes.EXERCISE 2: CULTIVATING & COMPARING FUNGAL GROWTHMolds and other fungi readily grow if they have an appropriate food source and ahospitable environment. You may have unwittingly discovered this if you have ever left an Fungi: Characteristics & ClassificationBIOL 1020orange or piece of bread sit for too long in the refrigerator or on the kitchen counter. In thisexercise you will design an experiment to evaluate how environmental factors influence thegrowth of molds. You will design your experiment to answer one of the following questions:1) Does mold grow faster at cold temperatures (in the refrigerator) or at warmtemperatures (in the room), or the same at both temperatures?2) Does mold grow faster in the light or in the dark, or the same in both light anddark?3) Does mold grow faster in a moist environment or one that is dry, or the same inboth moist and dry?4) Does mold grow faster on some substrates than it does on others, or does itgrow at the same rate on everything?MATERIALS:You will need one or more different substrate materials. You may choose to use bread(preferably one without preservatives), fruit, cheese, a leaf, or another organicsubstrate of your choice. You will only need more than one type of substrate if youopt to test question 4 above.Sealable sandwich-sized bags to hold the substrate you are testing.A marker to label the bagsDamp (not wet) paper towels.PROTOCOL:1.2.3.Choose one of the four questions above for your experiment. Formulate a hypothesisand record it in the question section below. Remember, a hypothesis is a statement ofthe expected outcome, so an appropriate hypothesis will indicate which, if either,environmental situation you expect will produce better mold growth.Design an experiment to test the question you have selected. Describe yourexperimental protocol in the question section below. Unless you are specificallytesting question 3, each of your bags should contain the chosen substrate plus adamp paper towel.Think about how to design your experiment to answer your question as clearlyas possible. Plan to have a pair of experimental conditions that differ in only onecharacteristic. For example, to test the effects of temperature put exactly thesame contents in all the bags and keep them all out of direct light, but keepsome of the bags at a different temperature. That way you can identify the causeof any differences in mold growth that you observe.Also, you will want to have at least two mold growth bags in each experimentalcondition to see whether results are consistent for different mold growth bagsunder the same condition. As stated above, these should be exact replicates.Allow the bags to sit undisturbed for four – six days. Check the bags each day.Record your observations in Table 1 below. If there is no noticeable growth, thatshould be noted. When fungi start to grow, they will appear fuzzy or hairy, and may begreen, white, black, yellow, or other colors. Bacterial colonies can be distinguishedfrom fungal colonies as they will appear shiny or slimy, although they may also bedifferent colors. Fungi: Characteristics & Classification4.BIOL 1020At the completion of the experimental time period, answer the remaining questionsbelow.TABLE 1. OBSERVATIONS OF FUNGAL GROWTH.Bag 1Bag 2Bag 3Bag 4Specificenvironmental condition foreach bag:Fill in thedates belowDay 1 (theday theexperimentwas started):Day 2:Day 3:Day 4:Day 5:Day 6:QUESTIONS:1.What question did you select to test?2.What is your hypothesis for this experiment?3.Write a paragraph to describe how you set up and carried out your experiment. Fungi: Characteristics & ClassificationBIOL 10204.Write a paragraph that summarizes the results you obtained from your experiment. Inyour summary you should compare all of the bags in a given experimental condition(e.g. all the bags at one temperature). Did you find the same result in all of the bagswithin each experimental condition? If you found differences between bags in thesame experimental condition, what might account for these differences? Yoursummary should also note any differences you noticed between the bags in differentexperimental conditions. For example, did mold growth differ depending ontemperature?5.Did your results support or refute your hypothesis? Explain.6.Based on the results from your experiments on mold growth, what can you concludeabout the factors that influence mold growth? What can you conclude about the bestways to store food?
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