Pre-Lab Questions 1: Use The Following Classifications To De

Pre-Lab Questions 1 Use The Following Classifications To Determine Whi

Use the following classifications to determine which organism is least related out of the three. Explain your rationale. Table 2: Classifications Classification Level American Green Tree Frog European Fire- Bellied Toad Eastern Newt Domain Eukarya Eukarya Eukarya Kingdom Animalia Animalia Animalia Phylum Chordata Chordata Chordata Class Amphibia Amphibia Amphibia Order Anura Anura Caudata Family Hylidae Bombinatoridae Salamandridae Genus Tursipops Bombina Notophthalmus Species cinerea bombina viridescens

How has DNA sequencing affected the science of classifying organisms?

You are on vacation and see an organism that you do not recognize. Discuss what possible steps you can take to classify it.

Experiment 1: Dichotomous Key Practice

A dichotomous key is an identification tool that starts with broad defining characteristics and splits into two options until an organism can be identified. In this experiment, you will identify organisms by their binomial nomenclature using a dichotomous key.

Materials: Dichotomous Key, Images of Organisms

Procedure:

1. Start by observing organism i (Figure 2). Once you have taken notice of its physical characteristics, use the dichotomous key (Figure 3) to identify the organism.
2. Start at number 1 on the key and decide if the organism has feature “1a” or feature “1b”.
3. Choose whichever option, and follow the dotted line to the next step marked “Go to #”.
4. Repeat this process at each step until arriving at a two-part scientific name.
5. Record your identification in Table 3.
6. Repeat these steps for all organisms in the dichotomous key (Figure 3).

Post-Lab Questions:

1. What do you notice about the options of each step as they go from number one up?
2. How does your answer from Question 1 relate to the Linnaean classification system?

Experiment 2: Classification of Organisms

Materials: Use Table 2 and the “tree” (Figure 4)

Procedure:

1. Select the first organism from Table 4 (E. coli).
2. Use the “tree” starting from the base, answering each question until the organism reaches the end of a “branch”. Write the organism's name in the red box.
3. Repeat for remaining organisms.
4. Fill in Table 2 with the correct kingdom for each organism based on your classification.

Post-Lab Questions:

1. Did this series of questions correctly organize each organism? Why or why not?
2. What additional questions would you ask to further categorize organisms within the kingdoms?
3. What questions might you have asked instead to classify these organisms?

Pre-Lab Questions (Bacterial Morphology & Handwashing)

1. Based on the scientific name Streptococcus agalactiae, what morphology would you expect these cells to have?
2. Name at least three animal structures analogous to bacterial flagella.
3. Hypothesize how over-washing hands can affect the population of “good” bacteria on human skin.

Experiment 1: Testing the Environment for Bacteria

Materials: Bleach solution, sterile swabs, nutrient agar, petri dishes, Parafilm®, marker, hot pad, microwave, refrigerator, scissors, notes about working with agar plates.

Procedure:

1. Liquefy agar by heating in microwave or hot water bath, ensuring even heating and cooling as needed.
2. Pour liquefied agar into petri dishes, let solidify in the refrigerator for 24 hours.
3. Remove plates, warm to room temperature.
4. Swab surfaces such as shoes, tables, teeth, bathroom doors, and shopping carts. Record each surface name.
5. Streak the surface onto the agar using sterile technique, label the plates, and seal with Parafilm®.
6. Incubate plates upside down in a warm area for 3 days, then observe bacterial growth.
7. Pour bleach solution over plates with growth, seal, and dispose of plates properly.

Post-Lab Questions:

1. Draw your plates, indicate the number of colonies, and describe their shapes.
2. Which plate had the most bacterial species? Was this expected? Why or why not?
3. Was the control plate free of colonies? If not, how might contamination have occurred?

Experiment 2: Measuring Antibiotic Resistance

Materials: Antibiotic discs (penicillin, ampicillin, kanamycin), forceps, nutrient agar plate with bacteria, ruler, Parafilm®.

Procedure:

1. Draw four quadrants on the bacterial lawn plate from the previous experiment.
2. Place each antibiotic disc into specified quadrants, avoiding contact outside designated areas.
3. Incubate for 3 days, then measure zones of inhibition around each disc.
4. Seal and dispose of plates appropriately.

Post-Lab Questions:

1. Did the bacterial lawn contain only one species? Why or why not?
2. Which antibiotic was most effective? Which was least effective?
3. What do differences in susceptibility suggest about the bacteria involved?

Writing a Formal Laboratory Report (Overview)

This report should include a title page, an introduction with background information and hypothesis, methods describing procedures or referencing standard protocols, results with detailed observations and data, a discussion interpreting the findings, and a references list formatted in APA style. Use internal citations for all referenced sources. The report should be comprehensive, clearly organized, and suitable for scientific publication.

References

• Brown, T. A. (2018). Genetics: A Molecular Approach. Garland Science.
• Madigan, M. T., Bender, K. S., Buckley, D. H., et al. (2018). Microbial Biotechnology. Pearson.
• Lewis, R. E. (2019). Bacterial Pathogenesis. Springer.
• Riley, D. R. (2020). Environmental Microbiology. CRC Press.
• Sherris, J. C. (2014). Antimicrobial Therapy. ASM Press.
• Venter, J. C., et al. (2001). The sequence of the human genome. Science, 291(5507), 1304-1351.
• Wilson, M. (2020). Microbiology: A Very Short Introduction. Oxford University Press.
• Madigan, M. T., et al. (2017). Brock Biology of Microorganisms. Pearson.
• Seifert, H. S., et al. (2018). Modern methods for bacterial classification. Annual Review of Microbiology, 72, 413-434.
• Yamamoto, K. R., & Setlow, P. (2010). DNA sequencing technologies. Nature Biotechnology, 28(8), 819–821.