In 2-3 sentences, describe the Hertzsprung-Russell diagram. What is it used for? What factors does it use to classify stars?

Explanation:

The Hertzsprung-Russell diagram is a graph that plots the temperature of a star against its absolute magnitude or luminosity. It was created by astronomers Ejnar Hertzsprung and Henry Norris Russell about 1910, and can be used to chart the life cycle or evolution of a star.

Meristematic tissue have the ability to divide themselves. It is the primary site for cell division and cell differentiation. It produces the new cells and are called growing tissue in plants. The new cells may or may not divide. It is the source of the regenerative potential of the plant.  

Cancerous cells can originate anywhere in the body and can spread into or invade adjoining tissues. It keeps growing and dividing relentlessly to form lumps. It can also break off and travel to distant tissues. Cancer cells rejects signals from other  cells.