Significance of Transpiration
Examination of the advantages (transpirational pull, cooling, mineral transport) and disadvantages of transpiration for plants.
What is Significance of Transpiration?
The process where moisture is carried through plants from roots to small pores on the underside of leaves, where it then changes to vapor and is released to the atmosphere.
Key points
- Explain the process and significance of transpiration.
- Describe how transpiration aids in water and mineral transport.
- Analyze the cooling effect of transpiration.
- Identify the potential disadvantages of excessive transpiration.
Common exam trap
Confusing transpiration with guttation.
Definitions
- Term
Transpiration
- Meaning
The process where moisture is carried through plants from roots to small pores on the underside of leaves, where it then changes to vapor and is released to the atmosphere.
- Term
Transpirational Pull
- Meaning
The force generated by the evaporation of water from the leaf surface that pulls water up through the xylem from the roots.
- Term
Stomata
- Meaning
Pores on the surface of leaves, stems, and other organs, that control the rate of gas exchange and water transpiration.
Learning objectives
Explain the process and significance of transpiration.
Describe how transpiration aids in water and mineral transport.
Analyze the cooling effect of transpiration.
Identify the potential disadvantages of excessive transpiration.
Relate transpiration to plant survival and adaptations.
Prerequisites
Understanding of plant cell structure (stomata).
Basic knowledge of water potential and osmosis.
Concept of xylem and phloem function.
Photosynthesis and its requirements.
Common mistakes
Confusing transpiration with guttation.
Underestimating the role of transpiration in mineral absorption.
Not considering the negative impact of excessive transpiration.
Forgetting that most water absorbed is lost.
Keywords
Transpiration
Water loss
Stomata
Xylem
Ascent of sap
Transpirational pull
Water potential
Cooling effect
Mineral transport
Plant physiology
Practice preview
Which of the following statements about transpiration is INCORRECT?…
medium
Which of the following conditions would MOST likely lead to a significant decrease in the rate of transpiration?…
medium
The cooling effect of transpiration is primarily due to:…
easy