The diagram shows two plant cells. Which statement describes what will happen to the water in the cells?
A) equal movement between cells
B) net movement from cell X to cell Y
C) net movement from cell Y to cell X
D) no movement between cells
▶️ Answer/Explanation
Ans: B
Osmosis is the movement of water from a region of lower solute concentration to higher solute concentration across a semi-permeable membrane. Cell X appears flaccid (low solute concentration), while Cell Y is turgid (high solute concentration). Thus, water will move from Cell X to Cell Y until equilibrium is reached.
Option A is incorrect because movement is unequal. Option C is the reverse of the correct direction. Option D is incorrect as osmosis will occur. Hence, the correct answer is B (net movement from cell X to cell Y).
The diagram shows the water potential of three plant cells. The more negative the value, the higher the solute concentration.
What is the immediate movement of water that will occur between the three cells?
A) from P to Q, and from R to P and Q
B) from Q to P and R only
C) from Q to P and R, and from P to R
D) from R to Q only
▶️ Answer/Explanation
Ans: A
Water moves from higher (less negative) to lower (more negative) water potential. R (-340 kPa) has highest water potential, so water moves from R to both P (-360 kPa) and Q (-400 kPa). P has higher potential than Q, so water also moves from P to Q. Therefore, correct answer is A.