Answer:
Adaptations develop from variations within a population and help organisms to survive in their given environment. Changes in populations accumulate over time; this is called evolution. The fossil record shows us that present-day life forms evolved from earlier different life forms.
Answer:Tissue
Explanation:Heart muscle cells beat in unison to push blood in timing with the rhythm of the heart, at the direction of nearby nerve cells. These muscle cells could best be called. Tissue. As cell division proceeds, the cells increase in number, but also become specialized in structure and function.
