Which of the following muscle types contains sarcomeres?

The correct answer highlights that skeletal and cardiac muscle contain sarcomeres, which are the basic contractile units of these types of muscle tissue. Sarcomeres are organized structures made up of actin and myosin filaments that enable muscle contractions through a sliding filament mechanism.

In skeletal muscle, the presence of multiple sarcomeres arranged in a repeating pattern gives the muscle its striated appearance, which is a key identifying feature of this muscle type. Similarly, cardiac muscle also exhibits striations and contains sarcomeres, allowing for coordinated contractions essential for the heart's pumping action.

In contrast, smooth muscle lacks sarcomeres, which is why it does not have a striated appearance. Smooth muscle fibers are organized differently and contract in a more gradual, sustained manner compared to the rapid and powerful contractions of skeletal and cardiac muscles. Hence, the inclusion of both skeletal and cardiac muscle in the correct answer underscores the significance of sarcomeres in these two muscle types while clarifying that smooth muscle does not possess this structure.