BRCA 1 and 2 are located in which chromosome?
**Core Concept**
The BRCA 1 and 2 genes are tumor suppressor genes that play a crucial role in maintaining genomic stability by participating in the repair of DNA double-strand breaks. They are located on specific chromosomes in the human genome.
**Why the Correct Answer is Right**
The BRCA 1 gene is located on chromosome 17q21, while the BRCA 2 gene is located on chromosome 13q12-13. These genes are essential for the repair of DNA damage through homologous recombination and non-homologous end joining pathways. Mutations in these genes can lead to an increased risk of breast, ovarian, and other cancers.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is incorrect as it does not specify the correct chromosome for BRCA 1 and 2.
* **Option B:** This option is incorrect as it is a different gene, not related to BRCA 1 and 2.
* **Option C:** This option is incorrect as it is not a specific chromosome number.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that mutations in BRCA 1 and 2 genes can significantly increase the risk of breast and ovarian cancer, and genetic testing is often recommended for individuals with a family history of these cancers.
**Correct Answer: D. 17q21 for BRCA 1 and 13q12-13 for BRCA 2**