Leaf Structure Flashcards
What is the order, from top to bottom, of the layers in a leaf?
Upper epidermis
Parisale mesophyll
Spongey mesophyll
Vein [xylem & phloem]
Lower epidermis [stoma, guard cells]
Features of xylem?
Dead cells, hollow, lignified
Why are xylems lignified?
To withstand the pressure of water
What is the direction of transpiration in the xylem?
Up
What is the direction of translocation in the phloem?
Up and down
What are the features of phloem?
Living tissue, sieve plates, companion cells
What do phloem transport?
Sugar
What are stomata?
The gaps in the lower epidermis of a leaf that allow for CO2 to enter the cells.
What are guard cells?
Cells that open or close the stomata to reduce/prevent water loss.
Increasing what factors increases the rate of transpiration?
Temperature, wind speed, surface area
Increasing what factor decreases the rate of transpiration?
Humidity
What is transpiration?
The process of water moving through a plant and its evaporation through the stomata.
What do companion cells do?
Provide energy for sieve cells
What is the thing used to measure the rate of transpiration?
Bubble potometer
Stages of transpiration
Water is absorbed by root hair cells through osmosis
Water travels up through the xylem
Water evaporates out of the stomata
