Question

what does the movement of an animal sperm flagellum and muscle contraction have in common?
a. they both involve motor proteins causing contraction (shortening) of cytoskeletal filaments.
b. they both involve microtubule depolymerization.
c. they both involve the sliding of cytoskeletal structures due to motor proteins.
d. they both involve the motor protein kinesin and atp.

Explanation:

The movement of an animal sperm flagellum and muscle contraction both rely on motor - proteins interacting with cytoskeletal elements. In sperm flagellum movement, dynein (a motor - protein) causes microtubules to slide relative to each other. In muscle contraction, myosin (a motor - protein) interacts with actin filaments causing sliding. Kinesin is not involved in muscle contraction or sperm flagellum movement in the way described in option D. Microtubule depolymerization is not the main mechanism in both cases. Option A is wrong as muscle contraction involves sliding not just shortening by contraction of filaments.

Answer:

C. They both involve the sliding of cytoskeletal structures due to motor proteins.