One of the primary advantages of cell culture is the ability to isolate a single type of cell from a multicellular organism. How has this advance changed the study of biology?
1: Single-type cultures are easier and cheaper to maintain than cultures made of mixed cell types.
2: Scientists can completely avoid using animal or human test subjects during their experiments.
3: Cultures with single cell types behave in culture exactly as they would behave in a tissue or organ.
4: Scientists know that any response during an experiment is associated only with that cell type.

Question

One of the primary advantages of cell culture is the ability to isolate a single type of cell from a multicellular organism. How has this advance changed the study of biology?
1: Single-type cultures are easier and cheaper to maintain than cultures made of mixed cell types.
2: Scientists can completely avoid using animal or human test subjects during their experiments.
3: Cultures with single cell types behave in culture exactly as they would behave in a tissue or organ.
4: Scientists know that any response during an experiment is associated only with that cell type.