What causes cells in living organisms to be different from one another?
O A An organism evolves new cell types in response to its environment
O B. The brain of an organism sends a signal to its cells to differentiate when the organismis in danger.
O c The DNA of an organism moves from one cell to another, allowing different cells to have different functions
O D. An organism expresses different genes at different times in development, causing cells to be specialized
The cell types in a multicellular organism become different from one another because they synthesize and accumulate different sets of RNA and protein molecules. They generally do this without altering the sequence of their DNA.