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.
It is useful for an ecologist to identify the keystone species in an ecosystem because the keystone species is important to maintaining the stability of an ecosystem, and any changes in the keystone species population shows that there is changes in ecosystem health.
A group of similar (accoding to function) types of cells, when comes together to perform a specific function, then it forms a tissues.
When a group of similarly working tissues come together then they form an organ.
And this relation could be written as
cell > tissue > organ
So, organ is a collection of tissues and tissues are collection of cells.
Answer:
three years old i think. sorry if its wrong