What is one example of biological variation that Darwin observed in his travels?

Hey me with this one❤❤❤❤ every organism needs food. does a cell also need it? explain very briefly.

Sea stars, sea urchins, sand dollars, and brittle stars are all memeber of a group, what is the common name of the group they are all in

{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.