Leaves Structure Flashcards
What is osmosis
Movement of water molecules from a high to low conc through a partially permeable membrane down the concwntration gradient
What will happen if a red blood cell was in pure water
The water molecules will move into the cell causing it to burst
What is the core practical for osmosis
-cut potatoes into cylinder
-make sure they are all the same length
-record each mass before
-add different amounts of sucrose solution into water
-leave for amount of time
-remove and dry the potatoes and record mass change
The higher the percent of sucrose solution the lower the mass will be because there will be a smaller mass of water in the potato
Name the layers of the leaf
Waxy cuticle
Upper epidermis
Palisade mesophyll
Spongy mesophyll
Lower epidermis
How is a leaf adapted to stop water loss
Waxy cuticle
Guard cells which open and close according to the amount if water
Why is the upper epidermis transparent
For sunlight to pass through to the palisade mesophyll for photosynthesis
What is a meristem tissue
Stem cells found in growth parts of the plant like tips of roots and shoots
What is active transport and where does it get it’s energy from
Movement of mineral particles across membrane from low top high concentration gets energy from respiration
How do plants absorb minerals
Can’t absorb by diffusion because its against the concentration gradient
They absorb it by root hair cells which also absorb water
What is transpiration and how
Evaporation of water from the leaves.
The movement of water up the plant from the roots then out the stomata
What is translocation
dissolved food is transported through the phloem in plants
Factors affecting transpiration
Temperature increases because more energy
Light increases because stomata open for longer
Wind increases the rate at which water diffuses out
Factors affecting photosynthesis
Light co2 temp lack of chlorophyll
What happens in light intensity during photosyntyesis
Goes up then plataues meaning other limiting factor
Co2 level affecting rate of photosynthesis
Goes up the platuaes means other limting factor
Temperature affecting photosynthesis
Rises then falls due to the enzymes becoming denatures
How do farmers increase the rate of photosynthesis
Green houses
Stops pests
Fake light when its dark
Pump more co2 into the atmosphere
Fertilisers
Paraffin which release light and co2
Photosynthesis equation
Carbon dioxide + Water -> Glucose + Oxygen
6Co² + 6H²O -> C⁶ H12 O⁶ + 6o²
Explain the process of diffusion in leafs
Water is taken from the soil by the roots then transported to the leaves via the xylem. The co2 diffuses into the leaves through the stomata
Why do plants want glucose
Save as starch for later or for respiration
What are the main uses of glucose in plants
Cellular respiratin-break down glucose to release energy
Make cellulose- makw strong cell walls
Make starch to store for later
What is the function of the stomata
Holes that allow gas exchange to take place
Allows oxygen and co2 to diffuse into and out of the leaf
Whu does the spongy mesophyll have air spaces. Hint-what does that layer need for photosynthesis
To allow oxygen and co2 to diffuse through the leaf
How is meristemtissue adapted to its function
Contains cells that are undifferentiated to allow mitosis to happen
