<span>Abnormal
behavior of cancer cells begins when a single cell undergoes
transformation, a process whereby a normal cell converts to a cancer
cell. Transformation occurs after a genetic change (mutation) in one or
more genes that encode for proteins in the cell cycle control system.
Because a transformed cell grows abnormally, the immune system normally
recognizes and destroys it.</span>
Just as the organs in an organ system work together to accomplish their task, so the different organ systems also cooperate to keep the body running. For example, the respiratory system and the circulatory system work closely together to deliver oxygen to cells and to get rid of the carbon dioxide the cells produce.
Answer:
Forest ecosystem or marine ecosystem.
Explanation:
Forest ecosystem is considered for his report because large number of organisms are present in forest ecosystem. Species diversity is greatest in the geographical location of tropics, particularly in tropical forests. Marine ecosystem is also considered for his report due to the presence of large number of different types of species particularly in coral reef which is a habitat of large number of organism.