How can scientists estimate the age of the solar system/Earth?

Most of earth’s fresh water is found in oceans and seas stored in glaciers and ice caps groundwater stored beneath the surface found in lakes, rivers, streams, and reservoirs

The first signs of cellular differentiation occur in the blastocyst. why is cellular differentiation important for the development of a fully formed human infant?

{answer found. it's (3 ) }which statement describes the cell cycle? (1)the cell cycle is a process in which one cell divides into four genetically different cells. (2)the cell cycle is a process in which one cell divides into two genetically different cells. (3)the cell cycle is a process in which one cell divides into two genetically identical cells. (4)the cell cycle is a process in which one cell divides into four genetically identical cells.