A group of students investigated how the salt content of water affects a plant that lives in an aquatic ecosystem. On one slide, the students placed a piece of a leaf of
an aquatic plant and then added a drop of tap water. On a second slide, they placed
a piece of the same leaf and then added a drop of 10% salt solution. The students
observed both leaf pieces with a microscope. They repeated the process three times.
The table below summarizes their findings.
Observations of Aquatic Plant Cells
Condition Cell Membrane Vacuole Chloroplasts
Slide 1: Leaf in tap
water
Just inside cell
wall
Large, fills most
of cell
Near edges of cell,
around vacuole
Slide 2: Leaf in
10% salt solution
Pulled away from
cell wall
Invisible
Clumped in center
of cell
Which statement is the BEST explanation for these findings?
a The 10% salt solution was hypertonic; the tap water was isotonic.
b The 10% salt solution was hypotonic; the tap water was hypertonic.
The 10% salt solution was isotonic; the tap water was hypertonic.
O The 10% salt solution was isotonic; the tap water was hypotonic.