You are sitting in lecture and you decide to leave the room for a minute. When you return, the professor is describing a cytoskeletal component and states that these fibres are thin and consist of two rows of protein subunits wound around each other in a long spiral. Since you left the room, you did not hear which cytoskeletal component is being referred to, but, since you read the book before you came to class, you know that it is
A) microfilaments.
B) the intermediate filaments.
C) the microtubules.
D) none of the above.

Question

Quizplus · Accepted Answer

Microfilaments are thin fibres made of actin proteins that are twisted around each other in a spiral, forming a double helix structure. This matches the description given by the professor, so A is the best choice. Intermediate filaments are not made of protein subunits wound around each other in a spiral, and microtubules are not thin fibers consisting of two rows of protein subunits.

You Are Sitting in Lecture and You Decide to Leave