3.4.2 Mass Transport in Plants Flashcards
What enviromental factors INCREASE the rate of transpiration
- Increasing temperature
- Decreasing humidity
- Increasing light intensity
- Increasing wind speed
What enviromental factors DECREASE the rate of transpiration
- Decreasing temperature
- Increasing humidity
- Decreasing light intensity
- Decreasing wind speed
Why does the rate of transpiration increase with increasing light intensity
Causes stomata to open
Why does the diameter of the xylem decrease as the rate of transpiration increases
- Water lost from the leaf in transpiration
- Creates more tension and pulling force on water molecules in xylem
What does water lost from the leaf in transpiration creating more tension and pulling force on water molecules in xylem create
The diameter of the xylem to decrease
What device is used to measure the rate of transpiration
Potometers
What are the vital procedures to setting up a potometer
- Cut stem underwater, and at a slant
- Ensure no air bubbles are present
- Seal joints with vasaline to ensure airtight
Why do potometers not truly measure the rate of transpiration
- Water used for support
- Water used in photosynthesis
- Water produced in aerobic respiration
- Apparatus not fully sealed
What is the benefit of xylem cells being dead, and therefore empty with no cytoplasm contents
Allows water to flow easier
What xylem specialisation allows water to flow easier
Cells are dead, and therefore empty with no cytoplasm contents
What is the benefit of xylem cells being long, forming tubes, with no end walls, meaning it’s hollow
Allows for continuous columns of water
What xylem specialisation allows continuous columns of water to flow
Cells are long, forming tubes, with no end walls meaning thay are hollow
What is the benefit of xylem cells having a thickened cell wall with cellulose and lignin
Support, and waterproofing
What xylem specialisation allows for support, and waterproofing
Thickened cell walls with cellulose and lignin
What is the benefit of xylem cells have pits in walls
Allows lateral movement of water