BIOLOGY-Plant Water Relations Questions and Answers

Practice Mode
Showing 10 of 50 questions
Q41
What is the main factor affecting transpiration rate in darkness?
  • A Stomatal closure
  • B Temperature
  • C Humidity
  • D Wind
Answer: Option A
Explanation: Stomata typically close in darkness, reducing transpiration regardless of other factors.
Q42
Which element deficiency affects water relation in plants?
  • A Potassium
  • B Nitrogen
  • C Phosphorus
  • D Sulfur
Answer: Option A
Explanation: Potassium deficiency impairs stomatal function and water regulation in plants.
Q43
What is the term for water movement through dead xylem cells?
  • A Conduction through dead cells
  • B Symplastic movement
  • C Apoplastic movement
  • D Transmembrane movement
Answer: Option A
Explanation: Xylem vessels and tracheids are dead at maturity and conduct water through their hollow lumens.
Q44
Which process is responsible for morning dew on grass?
  • A Guttation
  • B Transpiration
  • C Condensation
  • D Evaporation
Answer: Option A
Explanation: Guttation causes water droplet formation on plant surfaces, often confused with dew.
Q45
What is the term for plants adapted to saline environments?
  • A Halophytes
  • B Xerophytes
  • C Hydrophytes
  • D Mesophytes
Answer: Option A
Explanation: Halophytes have special mechanisms to grow in high-salt conditions like coastal areas.
Q46
Which process describes water uptake by seeds during germination?
  • A Imbibition
  • B Osmosis
  • C Diffusion
  • D Active transport
Answer: Option A
Explanation: Imbibition is the first step in seed germination, causing seed swelling and activation.
Q47
What is the main function of the cuticle in leaves?
  • A Reduce water loss
  • B Increase photosynthesis
  • C Enhance gas exchange
  • D Store water
Answer: Option A
Explanation: The waxy cuticle forms a waterproof barrier that reduces uncontrolled water loss from leaf surfaces.
Q48
Which process describes water movement from high to low water potential?
  • A Osmosis
  • B Diffusion
  • C Active transport
  • D Imbibition
Answer: Option A
Explanation: Water always moves from areas of higher water potential to lower water potential.
Q49
What is the term for the continuous water column in xylem?
  • A Water column
  • B Sap stream
  • C Transpiration stream
  • D Xylem flow
Answer: Option A
Explanation: The cohesion-tension theory depends on maintenance of an unbroken water column in xylem.
Q50
Which factor most affects transpiration in humid conditions?
  • A Humidity
  • B Temperature
  • C Light
  • D Wind
Answer: Option A
Explanation: High humidity reduces the vapor pressure deficit, slowing transpiration regardless of other factors.

📚 More from Medical Science

← All Topics 🎯 Practice ⏱️ Take Test 🔍 Search
Medical Science
Back to Medical Science
Other Subjects
Questions and Answers for Competitive Exams Various Entrance Test