All of the following statements about centrioles are correct EXCEPT they
A are located in the centrosome
B function in cell division
C are composed of microtubules
D function in protein synthesis
E occur in pairs
The correct answer and explanation is:
The correct answer is D. function in protein synthesis.
Centrioles are cylindrical structures composed of microtubules that play a vital role in the process of cell division. They are found in pairs within the centrosome, a region of the cell that organizes microtubules. Their main function is to help in the formation of the mitotic spindle during mitosis and meiosis. The spindle fibers, which are crucial for chromosome separation, originate from the centrioles.
Let’s break down the other statements:
- A. are located in the centrosome: This is true. The centrosome is the region of the cell that contains the pair of centrioles. It acts as a microtubule-organizing center (MTOC) and is crucial for organizing the spindle fibers during cell division.
- B. function in cell division: This is true. The centrioles are essential for cell division, specifically in organizing the spindle apparatus that segregates chromosomes into two daughter cells.
- C. are composed of microtubules: This is true. Centrioles are composed of nine sets of microtubule triplets arranged in a cylindrical pattern. These microtubules give the centrioles their structural integrity and play a role in their function during cell division.
- E. occur in pairs: This is true. Centrioles exist in pairs, and each pair is located within the centrosome. The two centrioles in a pair are oriented perpendicular to each other, and their coordination is essential for proper spindle formation during mitosis.
Centrioles do not participate in protein synthesis, which occurs in the ribosomes. Ribosomes are either free in the cytoplasm or attached to the endoplasmic reticulum, not in the centrioles. Hence, option D is the exception.