BIOLOGY-Plant Water Relations Questions and Answers
Practice ModeShowing 10 of 50 questions
Q11
What is the main function of root hairs in water absorption?
Answer: Option A
Explanation: Root hairs greatly increase the surface area for water and mineral absorption from soil.
Q12
Which ion plays a key role in stomatal opening?
Answer: Option A
Explanation: Potassium ions accumulate in guard cells, lowering water potential and causing water influx that opens stomata.
Q13
What is guttation?
Answer: Option A
Explanation: Guttation is the exudation of water droplets from leaf margins, often occurring at night when transpiration is low.
Q14
Which structure prevents air bubbles from entering the xylem?
Answer: Option A
Explanation: The Casparian strip in endodermal cell walls blocks apoplastic flow and forces water into symplastic pathway.
Q15
What is the water potential of pure water?
Answer: Option A
Explanation: Pure water has the highest possible water potential, defined as zero under standard conditions.
Q16
Which plant adaptation reduces transpiration in arid environments?
Answer: Option A
Explanation: Sunken stomata create a microclimate that reduces water vapor loss in xerophytic plants.
Q17
What is the term for the pressure developed in roots that pushes water upward?
Answer: Option A
Explanation: Root pressure results from osmotic movement of water into xylem and can cause guttation.
Q18
Which process describes water movement through living cytoplasm via plasmodesmata?
Answer: Option A
Explanation: The symplast pathway involves water movement through interconnected living cells via plasmodesmata.
Q19
What happens to a plant cell when placed in a hypotonic solution?
Answer: Option A
Explanation: In hypotonic solutions, water enters plant cells by osmosis, creating turgor pressure.
Q20
Which element is essential for maintaining stomatal function?
Answer: Option A
Explanation: Calcium acts as a second messenger in stomatal signaling and helps regulate guard cell movements.