The cells in the heart need a constant supply of nutrients / oxygen and to get rid of their waste products ans that why it needs its own special circulatory system.
Answer: If the cell membrane is unable to do its job properly, this can cause the cell to stop working properly. If many cells have bad cell membranes, the disease can affect an entire organ or even the whole body. In many of these cell membrane diseases, proteins within the cell membrane don't transport materials properly. Without the cell membrane, any chemical would be allowed to enter. Membranes are very important because they help protect the cell. Materials move across the membrane by diffusion. Diffusion is the movement of oxygen, nutrients, and other molecules.
Explanation:
D) all of the above
All of these are barriers to physical activity
<span>AIDS Rights Alliance of Southern Africa (ARASA)</span>
