Accumulation of which one of the following in the muscles of sprinters leads to cramp?

A sprinter feels cramps and pain in the thigh muscles after a run. This is due to accumulation of

Which one of the following is the structure of a cardiac muscle cell?

In eye donation, which one of the following parts of donors eyes is utilized?

Which of the following is responsible for muscle fatigue?

Which of the following is the smallest bone in the human body?