Projections of population growth. World population estimates from 1800 to 2100, based on high, medium and low United Nations projections in 2015 and UN historical estimates for pre-1950 data.
Answers. Best Answer: Cell-to-Cell communication is absolutely essential for multicellular organisms. The billions of cells of a human or an oak tree must communicate in order to develop from a fertilized egg and then survive and reproduce in turn.Communication among cells is also important for many unicellular organisms that must locate food and find mates in order to sexually reproduce.he process by which a signal on a cell's surface is converted into a specific cellular response, a series of steps called a signal-transduction pathway, has been extensively studied in many types of cells.
Cells communicate by sending and receiving signals. Signals may come from the environment, or they may come from other cells. In order to trigger a response, these signals must be transmitted across the cell membrane. Sometimes the signal itself can cross the membrane. Other times the signal works by interacting with receptor proteins that contact both the outside and inside of the cell.