Overall, life expectancy fell by one-tenth of a year, from 78.9 in 2014 to 78.8 in 2015, according to the latest data. The last time U.S. life expectancy at birth declined was in 1993, when it dropped from 75.6 to 75.4, according to World Bank data. The overall death rate rose 1.2 percent in 2015, its first uptick since 1999. More than 2.7 million people died, about 45 percent of them from heart disease or cancer.
The process by which new cells are made is called cell division. Cell division is occurring all the time. Around two trillion cell divisions occur in the average human body every day! Types of Cell Division. There are three main types of cell division: binary fission, mitosis, and meiosis.
Mitosis is the phase of the cell cycle where chromosomes in the nucleus are evenly divided between two cells. When the cell division process is complete, two daughter cells with identical genetic material are produced. Before a dividing cell enters mitosis, it undergoes a period of growth called interphase. Some 90 percent of a cell's time in the normal cellular cycle may be spent in interphase. G1 phase: The period prior to the synthesis of DNA. In this phase, the cell increases in mass in preparation for cell division. Note that the G in G1 represents gap and the 1 represents first, so the G1 phase is the first gap phase.â. S phase: The period during which DNA is synthesized.