The following is not an environmental factor that causes cancer: a mutation in the BRCA1 gene. The correct option is 1.
What is cancer?
Cancer is a disease, in which abnormal growth of cells, leads to tumors. Cancer can be occurred in any organ. The cell that grows rapidly is called cancerous cells.
Environmental factors are those factors that are present in the environment, like air, radiation, living organism, biotic factors, and abiotic factors.
Environmental factors that cause cancer are viruses, which are present in the environment, radiation, and chemicals, etc.
The BRCA1 is a gene that is an inheritance mutation and does not cause by an environmental factor. Gene mutation is when genetic changes occur in the sequence of the DNA.
Thus, the correct option is 1. a mutation in the BRCA1 gene
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