Cancer usually:
A) Is not inherited because the chromosomal changes usually occur in somatic cells.
B) Is not inherited because the chromosomal changes only occur in gametes.
C) is inherited, we now know it is invariably caused by certain genes.
The Correct Answer and Explanation is :
The correct answer is:
A) Is not inherited because the chromosomal changes usually occur in somatic cells.
Explanation:
Cancer is primarily a result of genetic mutations that occur in somatic cells, which are the non-reproductive cells in the body. Since somatic cells do not contribute to the formation of gametes (sperm and egg cells), these mutations are not passed on to offspring. Most cancers arise due to accumulated mutations from environmental factors such as exposure to carcinogens (e.g., tobacco smoke, radiation, or UV light), lifestyle choices, or simply errors in DNA replication over time.
While some cancers have a hereditary component, the vast majority are not inherited. In cases where cancer does run in families, it is often due to mutations in specific genes, such as BRCA1 and BRCA2 for breast and ovarian cancer. These mutations can be present in germline cells (sperm or eggs), making them heritable. However, these hereditary cancers account for only about 5-10% of all cancer cases.
For most cancers, the mutations occur in somatic cells, which divide and grow uncontrollably due to disruptions in genes regulating the cell cycle, such as tumor suppressor genes (e.g., TP53) or oncogenes (e.g., MYC, RAS). These mutations affect only the individual and do not get passed on to their children.
Thus, while some genetic predispositions can be inherited, cancer itself is typically not directly inherited, because the mutations causing it usually happen in somatic cells rather than the germline.
Image Generation
I will generate an image illustrating the difference between somatic and germline mutations, showing how somatic mutations lead to cancer but are not inherited.
Here is the generated image illustrating the difference between somatic and germline mutations. It visually explains how somatic mutations can lead to cancer but are not inherited, while germline mutations can be passed on to offspring. Let me know if you need any modifications!