Question

Cancer is a disease of uncontrolled cellular growth. A treatment for some types of cancer is the application of a spindle toxin which disrupts the formation of microtubules. Which organelle would be most affected by this treatment and how would it hinder the growth of cells?

1) Mitochondria, leading to a decrease in ATP production
2) Golgi apparatus, causing disruption in protein processing and secretion
3) Endoplasmic reticulum, resulting in impaired protein synthesis
4) Centrioles, leading to abnormal cell division

Answer 1

Chemotherapy drugs like vincristine and colchicines disrupt mitosis by targeting mitotic spindles, made of microtubules, and hindering their assembly. This affects the centrioles and leads to abnormal cell division, as the spindle fibers cannot form properly to separate chromosomes. so, option 4 is the correct answer.

Step-by-step explanation:

Cancer is characterized by uncontrolled cellular growth where cells no longer follow the normal regulations of the cell cycle. Chemotherapy drugs such as vincristine and colchicines target microtubules during cell division, specifically affecting the mitotic spindles. These spindles are crucial for chromosome separation during mitosis, especially in the metaphase where chromosomes line up in the center of the cell. By binding to tubulin, the drugs prevent the microtubules from assembling and disassembling, which in turn inhibits spindle formation. This disruption of microtubule dynamics ultimately leads to an abnormal cell division process.

Answering the initial question, the spindle toxin would most impact the centrioles, organelles that are important for forming the spindle fibers. The hinderance in spindle fiber formation due to the inhibitor would lead to abnormal cell division, making option 4 correct: "Centrioles, leading to abnormal cell division."