When elements combine chemically why are they not easily identifiable

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Multicellular organisms use cell division, mitosis, for growth and the maintenance and repair of cells and tissues. single-celled organisms may use cell division as their method of reproduction. regardless of the reason for mitosis, the process ensures genetic continuity. what is the step in the cell cycle that ensure genetic continuity?

Identify any four organelles that should be present in the eukaryotic organism and describe the function of each organelle