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A naturally occurring cell protein (nm23) has been shown to inhibit the activity of cancer cells - Scottish Highers Human Biology - Question 3 - 2016
Question 3
A naturally occurring cell protein (nm23) has been shown to inhibit the activity of cancer cells. Individuals produce varying levels of this protein depending on th... show full transcript
Worked Solution & Example Answer:A naturally occurring cell protein (nm23) has been shown to inhibit the activity of cancer cells - Scottish Highers Human Biology - Question 3 - 2016
Step 1
Calculate how many of the 1000 women would be expected to survive for 4 years after diagnosis.
Answer
From the graph, we find that approximately 74.2% of patients with normal levels of the protein survived after 4 years. Therefore, to find out how many of the 1000 women survived, we can use the formula:
Substituting in the values gives:
Thus, approximately 742 women would be expected to survive for 4 years after diagnosis.
Step 2
Use data from the graph to describe the changes in the percentage of surviving breast cancer patients with normal levels of the protein during the study.
Answer
Between 0 and 7 years after diagnosis, the percentage of surviving patients decreased significantly. Initially, it started at 100% and fell to around 62% by the end of the 7-year mark. From 7 to 9 years, the percentage remained constant at 62%, indicating a stabilization in the survival rates during this period.
Step 3
Describe how cancer can develop and spread through the body.
Answer
Cancer can develop when cells start to divide excessively and lead to the formation of abnormal cells or tumors. These cells do not respond to the usual regulatory signals that control cell division. Additionally, cancerous cells can detach from the original tumor and spread to other parts of the body through the bloodstream or lymphatic system, leading to the formation of secondary tumors, a process known as metastasis.