Vertebrates and invertebrates
Answer:
A band - light central region of sarcomere.
Explanation:
Sarcomere is the basic structural unit of the skeletal muscles. These sarcomere shows striations ( light and dark bands) when veiw under the microscope.
A band or anisotropic band is the dark region of sarcomere. A band consists of both thick and thin filaments of actin and myosin proteins. The A band has the ability to refract light and appears dark.
Thus, the correct answer is option (D).
