Final answer:
Cytoskeletal filaments are ranked from smallest to largest in diameter as microfilaments, intermediate filaments, and microtubules. Microfilaments have a diameter of about 7 nm, intermediate filaments range from 8 to 10 nm, and microtubules are about 23 nm in diameter. (option 1)
Step-by-step explanation:
The correct ranking, starting with the smallest in diameter to the largest, is as follows: microfilaments (1), intermediate filaments (2), and microtubules (3).
Therefore, the correct answer is option 1) Microfilaments, Intermediate filaments, Microtubules.
Microfilaments, also known as actin filaments, are the narrowest of the cytoskeletal fibers with a diameter of about 7 nm. They consist of two intertwined strands of actin, a globular protein, and are responsible for various functions including cellular movement and maintaining cell shape.
Intermediate filaments are made of strands of fibrous proteins, like keratin, wound together and have a diameter ranging from 8 to 10 nm. These filaments provide mechanical strength to the cell and help maintain its shape by resisting tensile forces.
Microtubules are the thickest of the cytoskeletal fibers, forming hollow tubes with a diameter of 23 nm made of tubulin dimers. They play a crucial role in maintaining the cell's structure, facilitating organelle movement, and are involved in cell division by forming the mitotic spindle.