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Question 19
Cancer is caused by changes in cells. (a) Describe the effects that cancer has on cells. (b) Cells usually become cancerous due to damage to their DNA.... show full transcript
Step 1
Answer
Cancer affects cells in several ways:
Uncontrolled Growth: Cancer cells proliferate uncontrollably, leading to an increase in cell numbers and a lump or mass called a tumor.
Invasion of Surrounding Tissues: Cancer cells can invade nearby tissues and organs, disrupting their normal structures and functions.
Metastasis: Cancer cells can spread to distant parts of the body through the bloodstream or lymphatic system, leading to secondary tumors in organs such as the lungs, liver, or bones.
Altered Cell Function: Cancer cells often lose the ability to perform the functions of normal cells, affecting physiological processes in the body.
Step 2
Answer
To calculate how many females in the UK could develop breast cancer due to a mutation in the BRCA gene:
Calculate the number of females with a mutation in the BRCA gene:
The total number of females is .
The fraction of females with a mutation is given as 1 in 400, so:
.
Calculate the number likely to develop breast cancer:
Given that 60% of women with this mutation are likely to develop breast cancer:
.
Therefore, the answer in standard form is:
.
Step 3
Answer
Operating to remove a brain tumour can produce side effects for several reasons:
Proximity to Critical Structures: The brain is a vital organ containing many critical structures, including neurons that control bodily functions. Surgery may inadvertently damage these structures, leading to side effects.
Swelling and Inflammation: Post-surgery inflammation can cause swelling in the brain, which might lead to increased pressure and various neurological complications.
Neurological Deficits: Depending on the tumor's location, removal might result in changes in cognitive function, movement, speech, or sensory perception, leading to long-term or permanent deficits.
In summary, one possible side effect could be neurological deficits resulting from damage to surrounding brain tissue.
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