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DEMONSTRATION OF THE UBIQUITY OF MICROORGANISMS Biology Lab work Author: Georgina Rodrigues OBJECTIVES Demonstrate the ubiquity of microorganisms Detect their presence in different habitats specifically: soil and old leaves MATERIAL Petri dish with culture medium Y.M.A. Alcohol lamp Timer Soil Old leaves

PROCEDURE 1- Choose two places where it’s possible find microorganisms. 2- Put in each place three petri plates with YEPD medium and three with LB medium. Mark properly plates, at the bottom, in order to identify the work subsequently (name, date, culture medium, other important information: time, dilution, and so on) 3- Open plates and close only after 5, 60 and 160 minutes respectively. 4- In other plate put a small amount of soil 5- Use other plate to put a old leaf. 6- Idealize other conditions where it’s possible find microorganisms. 7- Incubate 3-4- days at environmental temperature. 8- After incubation, keep plates in refrigerator until next lesson, properly packed. 9- Observe the plates and, as it is possible, record the number of colonies and the number of different colonies. 10- Interpret the results and describe morphological colonies characteristics (flat, rough, granulate, filamentous, and so on) and optical (color, transparency, brightness, and so on) colonies characteristics It intends pupils be able detect the presence of microorganisms in very different habitats, to make a note of observations that can distinguish the big groups of microorganisms presents and establish, based on morphological observation of organisms, independently of the particular habitat, 3 or 4 groups that reveals significantly distinct from each other and similar within each group.

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