Y8 Science | Photosynthesis Flashcards
What is photosynthesis? (simple version)
How plants make food from sunlight
What is photosynthesis (detailed version)
Building glucose from carbon dioxide and water using light
Name one use of glucose in plants.
Respiration/Make and strengthen cellulose cell wall/Make starch for storage/Make lipids as energy store
Where does photosynthesis occur in the cell?
Chloroplast
Name the pigment in chloroplasts that absorbs light.
Chlorophyll
State the word equation for photosynthesis
Carbon dioxide + water -> glucose + oxygen
Is photosynthesis endothermic or exothermic?
Endothermic
How does water enter plants?
Diffusion into root hair cells, transported through xylem
Name the three organs in a plant
Roots, stem, leaf
How do gases move in and out of plants?
Diffusion through tiny holes (stomata) on underside of leaf
State an adaptation of the leaf for efficient photosynthesis.
Broad leaves/Thin/Have chlorophyll/Air spaces/Guard cells to regulate stomata opening/veins
What is the function of the waxy cuticle?
To protect the leaf and reduce evaporation of water
What is the function of the palisade cells in top layer of leaf??
To absorb light for photosynthesis
What is the function of the spongy layer?
Creates spaces to allow CO2 to diffuse into the leaf
State three ways that a leaf is adapted for gas exchange
Large surface area, thin, stomata
Give an example of diffusion occurring in a plant
Gas exchange (oxygen and carbon dioxide)
Define “transpiration”
Evaporation of water from a leaf
How can you show a plant is photosynthesising?
Test it for starch (chains of glucose)
What is starch?
An insoluble store of glucose
How is starch formed in a plant?
During photosynthesis
Which substance is used to test for the presence of starch?
Iodine solution
What is the colour of iodine solution if starch is present?
Blue/black
What are the stages for testing a leaf for starch?
boil leaf, add into boiling ethanol, spread onto white tile, add iodine to test for starch
What minerals do plants need?
nitrates, phosphates, magnesium, potassium