Why does the life span of different animal/plant species vary?
Plants and animals are very different to start with of course. The main difference between how old an individual animal species gets is to do with the number of times their cells can divide..this is preprogrammed into a particular part of the chromosome called teleomere. Life cycles of animals differ in length because they use up their amount of cell divisions quicker so to speak. After a set number of copies/cell divisions a cell undergoes programmed cell death, cell suidice in effect. I believe trees undergo much less cell division as they grow older then animals, but there might be more differences which cause the amazing life length differences as well….
