Written Assignment 1: Trace the Scientific Method in a Primary Research Scientific Article
Addresses course outcomes 1 and 4:
use knowledge of biological principles and the scientific method to ask and answer relevant questions about the human body
weigh and make health-related decisions based on an understanding of the value and limits of scientific knowledge and the scientific method
Before attempting this assignment, you might want to revisit the Scientific Method Tutorial in the Science Learning Center under the Course Content area.
Substance in Green Tea Inhibits Inflammatory Breast Cancer Cells
Inflammatory breast cancer (IBC) is a rare and often fatal form of breast cancer. In IBC, lymphatic vessels in the skin are blocked causing the breasts to appear swollen and red. Early in the disease process, patients with IBC usually do not have the classic “lump” in their breast; therefore the disease is frequently diagnosed at later stages. Diagnosis is often so delayed that the cancer has metastasized and patient prognosis is poor.
The underlying cause of IBC is unknown, but it is believed that like with other cancers cetain cell types have the abililty to transform into cells that can form malignant tumors. These aberrant cells are considered cancer stem cells, and populations of cancer stem cells have been identified in IBC.
In a recent, study researchers evaluated whether a metabolite found in green tea could inhibit the growth of certain stem cell types that have been identified in the breast tissue of patients with IBC. In this study, two IBC stem cell types, SUM-149 and SUM-190, were exposed epigallocatechin-3-gallate (EGCG- is a potent antioxidant found in green tea). Results from the study showed that EGCG treatment inhibited the growth, spread, and survival of the two stem cell types.
For the following questions, please refer to the original paper. The link to the paper is: http://www.plosone.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0073464&representation=PDF
What is the overall hypothesis of this experiment? (Reminder: a hypothesis is a statement that can be tested).
In the Materials and Methods section of the paper, the authors discuss the cell culture and treatment conditions. What was the control group treated with in this section (make sure to look only at the Cell Culture and Treatment section of the paper)? Why?
Again, looking only at the Cell Culture and Treatment section, what was the experimental group treated with? Why?
In the Results section of the paper, the authors clearly summary their multiple findings. In the “EGCG Reduces Growth of Pre-existing Tumors Derived from SUM-149 Stem-like Cells” results sub-section, the authors report a specfic finding. What specific result do the researchers report?
Did the researchers follow the scientific method in their experimental design? Explain.
Based on the results, was the hypothesis supported, and what can you conclude from this experiment?
Mineva et al. (2013). Epigallocatechin-3-gallate inhibits stem-like inflammatory breast cancer cells. PLoS ONE, 8(9): e73464. Doi:10.1371/journal.pone.0073464
Rubric Name: Writtent Assignment 1: Trace the Scientific Method Assignment
hypothesis clearly stated without any mistakes, concisely
hypothesis of the experiment stated, but contains too much information
an attempt to state hypothesis, with some correct information and/or components
hypothesis not stated
control group identified correctly; treatment of the control group described and sound reasoning present
control group identified correctly; treatment described with minor mistakes and/or minor mistakes in reasoning
control group identified, reasoning is missing
control group not identified, remained of the question not answered
experimental group identified correctly; treatment of the experimental group described and sound reasoning present
experimental group identified correctly; treatment described with minor mistakes and/or minor mistakes in reasoning
experimental group identified, reasoning missing
experimental group nor reasoning present
clear answer with concrete results from the experiment
1 mistake in the results, may be lacking clarity, but overall is factually accurate
2 mistakes, significant flaws in clarity
Not answered or answered incorrectly
accurately identifies and describes components of the scientific method and how it was applied in the experiment
one component of the scientific method is not explained as it applies to the experiment in question; minor mistakes present, overall factually accurate response
2 or more components are missing or not explained; conclusion contains more factually incorrect information
answer incorrect or not submitted
accurate response and rationale
accurate response, rationale lacking detail or contains minor mistakes, but overall is factually correct
response shows lack of understanding of the experimental results and hypothesis, conclusion contains major mistakes
answer not submitted or completely incorrect