Question

Which of the following is not a feature of cardiac muscle? Multiple Choice They depend almost exclusively on aerobic respiration. They are rich in glycogen. They are very rich in myoglobin. They have larger than average mitochondria. They have about the same endurance as skeletal muscle fibers.

Answer 1

The answer is: they are rich is glycogen

Step-by-step explanation:

Cardiac muscle which is found only in the walls of the heart is striated and multi nucleated, and its contractions are not under controlled by the autonomic nervous system. It is highly resistant to fatigue due to the presence of a large number of mitochondria, myoglobin and a good blood supply allowing continuous aerobic metabolism.

However the glycogen is majorly stored in the skeletal muscle and liver, not the cardiac muscle.

Answer 2

The correct answer will be option-They have about the same endurance as skeletal muscle fibers.

Step-by-step explanation:

Cardiac muscle is one of the three types of muscle which is present in the Heart of the organism.

The muscle fibres of the cardiac muscle possess a high amount of myoglobin- an Oxygen carrying molecule which can store the oxygen for some time.

The cardiac muscles have to pump blood in the body, for which they require a high amount of ATP, so they possess larger mitochondria.

The studies have shown that the cardiac muscles store glycogen carbohydrate which is used during the relaxation phase in stress conditions.

Since the cardiac muscles do not have the same endurance as the skeletal muscles which with physical exercise can be increased therefore the selected option is the correct answer.