How do the structures of the cardiac muscle and skin tissue support their functions within the body?

Cardiac muscle tissue works to keep your heart pumping through involuntary movements. This is one feature that differentiates it from skeletal muscle tissue, which you can control. It does this through specialized cells called pacemaker cells. These control the contractions of your heart.

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answer; ///(b) it is composed of four protein chains and four heme groups;

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.