When a cell sits in a hypotonic solution, water:

1. Hypo means the outside fluid holds fewer solutes than the cytoplasm. 2. Water moves toward the side with more solute. 3. In a hypotonic situation the extracellular fluid has a lower concentration of solutes, so water enters the cell. 4. The cell swells and may possibly burst as a result. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 5 'Structure and Function of Plasma Membranes', sections 5.1-5.4_