The Scientific Method Paper - Case Study Example

The Scientific Method The scientific method provides a plan for testing the validity of a ment based on the observation of natural phenomenon. A standard process of questioning and analysis is followed to obtain data to test a hypothesis or educated guess. Scientists all around the world follow this same procedure to test questions about natural phenomenon. In this way, data is normalized for results and can be compared and retested by laboratories around the world. The procedure does not have to be performed only in laboratories.

The scientific method is employed by scientists at any locale, from field experiments to the most sophisticated centers for science. The following list is a summary from the plant experiment described on the course website: Observation: Plants grow toward the light. Question: Why do plants grow toward the light? Hypothesis: Plants grow toward the light because they use the light to produce their food. Prediction: If I place plants near the light, the leaves will grow toward the light. If I place plants in the center of the room, they will not turn their leaves in any particular direction.

Testing: perform the experiment control group-place three plants in the center of the room experimental group- place three plants near the light data-record the direction of the plants’ leaves after a one week period conclusions-Plants grow toward the light because they convert light to food. Plants near the window turn their leaves toward the light. Plants grown in the center of the room do not turn their leaves in any particular direction. Another observation which can be examined by the scientific method is that refrigeration slows down the rate of growth of fungus.

Observation: Fungus grows on cheese left at room temperature faster than cheese left in the refrigerator. Question: Why does fungus grow on cheese left at room temperature faster than cheese in the refrigerator? Hypothesis: Refrigeration slows down the rate of fungal growth on cheese. Prediction: If I leave cheese at room temperature, fungus will grow on it faster than cheese in the refrigerator. Testing: perform the experiment control group- place three pieces of cheese in the refrigerator experimental group- place three pieces of cheese at room temperature data- after one week, record the number of fungal colonies on the cheese in the refrigerator and on the cheese at room temperature.

conclusions- There are more fungal colonies on the cheese at room temperature compared to the cheese in the refrigerator. Fungal spores are present in the air and, if they contact a food source, they will grow to make colonies (Stanier et Al., 1986). Refrigeration slows down the metabolism and therefore the growth rate of fungal spores (Pelczar et Al., 1986). Performing the scientific method to address a specific question often results in more questions. In the case of fungal colonies growing on cheese, you could ask the question “How can I more accurately measure the reduction of the fungus growth due to refrigeration?

” To answer this question, you could perform the experiment with liquid media and quantify the density of growth in the refrigerator or at room temperature by placing the culture tubes in a spectrophotometer and measuring the density of the cultures. You could also ask the question, “What is the identity of the fungus in the colonies?” You could address this question by determining the metabolic profile of the fungus. This can be done by determining which biochemical substrates are utilized in the growth of the fungus.

More sophisticated questions may include “What is the total protein content of the culture grown at room temperature versus the culture in refrigeration?” This could be addresses by isolating total protein from both cultures and subjecting them to polyacrylamide gel electrophoresis and staining the gels with a dye. You could more accurately determine the identity of the fungus by isolating total DNA and sequencing a gene to compare with a molecular phylogenetic tree of fungi. Even more sophisticated methods for quantifying fungal growth might include the incorporation of radioactively-labeled amino acids into fungal proteins.

You could add the radioactively labeled amino acids to the cultures and isolate total biomass via filtration and then place the fungal filters in a scintillation counter to determine total radioactivity and consequently total protein biomass. You would expect that the refrigerated culture would contain less total radioactivity due to reduced metabolism and therefore reduced fungal growth. References Stanier, R., Ingraham, J., Wheelis, M., Painter, P. (1986). The microbial world. Prentice-Hall, New Jersey. 689 pp. Pelczar, M., Chan, E., Krieg, N. (1986). Microbiology.

McGraw-Hill, New York. 917 pp.