地球上的生物为什么一定会死亡?无论是科学家还是普通人都热切地关注着这个问题。科学家们曾在细胞的染色体顶端发现了一种物质,被称为“端粒”,细胞每分裂一次,端粒就缩短一点。人的正常体细胞的平均分裂次数是50次,这时,端粒已无法再缩短了,于是细胞也就死亡。这是促使生命逐渐衰老直至死亡的一个重要原因,其他还有氧化作用、DNA损伤等也能促使生命衰老。 Why do the creatures of the earth die? Both scientists and ordinary people are eagerly concerned about this issue. Scientists had discovered a substance at the top of the cell’s chromosome called “telomere,” and each time the cell divides, the telomere shortens. The normal number of normal somatic cell divisions is 50 times. At this time, the telomeres can no longer be shortened, and the cells die. This is an important cause of the gradual aging of life to death, and other oxidative effects, DNA damage, etc. can also promote life aging.