Answer:
Oceanic crust and continental crust
Scientific modeling is a scientific activity, the aim of which is also to make something a particular part or feature of the word easier to recognize, define, quantify, visualize, or even simulate by referencing it to an existing and usually commonly accepted knowledge.
Answer:
Lysosome - Janitor, cleans up food particles, waste, and dead cell parts.
Nucleus - Principal, contains DNA and is the control center for the cell.
Cell Membrane - Basically the walls of the school building
Ribosomes - Cafeteria Workers, creates "food" by combining amino acids.
Hope this helps!
There are three sources of genetic variation: mutation, gene flow, and sexual reproduction. A mutation is simply a change in the DNA.