Examples of Common Oncogenes and Tumor Suppressor Genes.

📚 Quick Study Guide

• 🧬 Oncogenes: These genes promote cell growth and division. They are often mutated forms of proto-oncogenes.
• 🔥 Proto-oncogenes: Normal genes that can become oncogenes if mutated or expressed at abnormally high levels.
• 🚫 Tumor Suppressor Genes: These genes regulate cell division and prevent uncontrolled growth. They act as brakes on cell proliferation.
• 🛠️ Loss of Function: Mutations in tumor suppressor genes often result in a loss of their normal function, leading to cancer.
• 📈 Gain of Function: Mutations in proto-oncogenes that create oncogenes usually lead to a gain of function, promoting excessive cell growth.
• 🔑 Key Examples: Common oncogenes include $RAS$, $MYC$, and $ERBB2$. Common tumor suppressor genes include $TP53$, $RB1$, and $BRCA1$.
• 🔄 Balance: The balance between oncogene and tumor suppressor gene activity is critical for maintaining normal cell growth and preventing cancer.

🧪 Practice Quiz

1. Question 1: Which of the following is an example of an oncogene?
   1. A) TP53
   2. B) BRCA1
   3. C) RAS
   4. D) RB1
2. Question 2: What is the normal function of a proto-oncogene?
   1. A) To suppress cell growth
   2. B) To promote controlled cell growth and division
   3. C) To repair damaged DNA
   4. D) To induce apoptosis
3. Question 3: Which type of mutation typically leads to the activation of an oncogene?
   1. A) Loss-of-function mutation
   2. B) Silent mutation
   3. C) Gain-of-function mutation
   4. D) Frameshift mutation
4. Question 4: Which of the following is a well-known tumor suppressor gene?
   1. A) MYC
   2. B) ERBB2
   3. C) RAS
   4. D) TP53
5. Question 5: What is the primary role of tumor suppressor genes in preventing cancer?
   1. A) Promoting cell growth
   2. B) Inhibiting cell division and growth
   3. C) Repairing damaged DNA
   4. D) Inducing angiogenesis
6. Question 6: A mutation in which gene is commonly associated with increased risk of breast and ovarian cancer?
   1. A) RAS
   2. B) MYC
   3. C) BRCA1
   4. D) ERBB2
7. Question 7: What happens when a tumor suppressor gene experiences a loss-of-function mutation?
   1. A) Uncontrolled cell growth
   2. B) Increased DNA repair
   3. C) Apoptosis induction
   4. D) Decreased cell division