cells -> gills -> tissues cells -> tissues -> gills gills -> tissues -> cells tissues -> gills -> cells
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of the following correctly orders part of a fish's respiratory system from the least complex to most complex?
Possibilities:
- cells -> gills -> tissues
- cells -> tissues -> gills
- gills -> tissues -> cells
- tissues -> gills -> cells

cells -> tissues -> gills