Which of the following best describes the water potential (\( \Psi \)) of a zucchini cube placed in pure water at atmospheric pressure?

• A. It is less than zero (\( \Psi < 0 \))
• B. It is greater than zero (\( \Psi > 0 \))
• C. It is equal to zero (\( \Psi = 0 \))
• D. It is always positive regardless of the environment

Answer: (A)

Verified step by step guidance

1. Understand the concept of water potential ( $\Psi$ ): Water potential is a measure of the potential energy of water in a system compared to pure water, under standard conditions. It determines the direction of water movement and is influenced by solute concentration and pressure.
2. Recall the formula for water potential: $\Psi =\Psi$_p + Ψ_s , where $\Psi$_p is the pressure potential and $\Psi$_s is the solute potential. Pure water has a solute potential ( $\Psi$_s ) of zero.
3. Consider the zucchini cube: Zucchini cells contain solutes, which lower the solute potential ( $\Psi$_s ) below zero. This means the overall water potential ( $\Psi$ ) of the zucchini cube will be less than zero.
4. Analyze the environment: The zucchini cube is placed in pure water, which has a water potential ( $\Psi$ ) of zero. Water will move from the area of higher water potential (pure water) to the area of lower water potential (zucchini cube).
5. Conclude the answer: Based on the above reasoning, the water potential ( $\Psi$ ) of the zucchini cube is less than zero, as it contains solutes that lower its solute potential.