B6 Otganisation In Plants Flashcards
Y is a leaf an organ?
There are many tissues inside the leaf that work together to perform photosynthesis
How is the upper epidermis adapted for its function ?
The single layer of transparent cells allows light to pass through
The cells secrete a waxy substance to make leaves waterproof
How is the palisade mesophyll adapted for its function?
The palisade mesophyll is tightly packed with lots of chloroplasts to absorb as much light as possible for photosynthesis
How is the spongy mesophyll adapted for its function?
The air spaces increase the surface area and allow gases to diffuse quickly
What is the function of the guard cells?
To control the opening and closing of the stomata
What is the function of the xylem?
To transport water and mineral ions from the roots to the rest of the plant
Give three adaptations of the xylem
Made of dead cells
No end wall between cells
Walls strengthened by a chemical called lignin to withstand the pressure of the water
What is the function of the phloem?
To transport dissolved sugars from the leaves to the rest of the plant
What is the purpose of translocation?
To transport dissolved sugars from the leaves to other parts of the plant for respiration, growth and storage
Transpiration definition ?
The movement of water from the roots to the leaves through the xylem
Transpiration purpose?
Provide water to keep cells turgid
Provide water to cells for photosynthesis
Transport mineral ions to leaves
Name four factors that affect the rate of transpiration
Temperature
Light intensity
Humidity
Wind speed
What effect does temperature have on the rate of transpiration ?
They increase the rate of transpiration.
What effect does humidity have on the rate of transpiration?
Higher levels of humidity decreases the rate of transpiration
Y does increased light intensity increase the rate of transpiration?
The stomata opens wider to let more CO2 into the leaf for photosynthesis
