Spindle fibers are made of

• A. Actin protein and RNA
• B. Cellulose and RNA
• C. Tubulin protein and RNA
• D. Both (A) and (C)

Spindle fibers play a crucial role during cell division, specifically in the process of mitosis and meiosis. They are primarily composed of proteins that help in the separation of chromosomes.

Composition of Spindle Fibers

The correct answer to your question is C. Tubulin protein and RNA. Spindle fibers are mainly made up of tubulin, which is a type of protein that forms microtubules. These microtubules are essential for the movement and organization of chromosomes during cell division.

Why Not the Other Options?

• A. Actin protein and RNA: Actin is involved in muscle contraction and cell movement, not spindle fibers.
• B. Cellulose and RNA: Cellulose is a structural component in plant cell walls, not related to spindle fibers.
• D. Both (A) and (C): Since option A is incorrect, this option cannot be correct either.

In summary, spindle fibers are primarily made of tubulin protein, which is essential for their function during cell division.