Question

Longevity: Maximum human lifespan is ___-___ years.

- _____: Each species is subject to a time limit beyond which cells simply lose the capacity to replicate themselves. Embryo cell - _____ multiplies; Adult cell - ___ multiplies

Answer 1

The maximum human lifespan has been identified at between 115 and 125 years. As humans develop from embryo to adult, cell division rates vary and are tightly regulated. Adult cell division mainly serves tissue repair and regeneration, with certain cells like muscle or nerve cells remaining in the non-dividing G0 phase for a lifetime.

Step-by-step explanation:

The maximum human lifespan is typically defined as 115-125 years. Researchers have posited that there might be an upper limit to old age, but with advances in healthcare, this number could potentially increase. The longevity of an individual relates to a species' ability to replicate cells over time. There are various factors at play, including programmed factors like telomere shortening and damage-related factors such as DNA mutations due to environmental factors.

In the context of cell division, embryo cells multiply rapidly, aiding in the development of a complex, multicellular organism from a single zygote. In contrast, adult cells divide at a slower rate and are primarily responsible for the repair and regeneration of tissues. Some cells, like muscle or nerve cells, may remain in the G0 phase for a lifetime, which means they do not divide. The cell cycle and its regulation are crucial for the maintenance of healthy bodily function, and disruptions can have significant consequences.