Plants And Photosynthesis Flashcards
(27 cards)
What is photosynthesis?
A series of enzyme-controlled reactions in plant cells.
What absorbs light energy for photosynthesis?
Chlorophyll absorbs light energy for the reaction.
What is the organ of photosynthesis?
The leaf is the organ of photosynthesis.
What are the products of photosynthesis?
Transformed into cellulose, proteins, and oils; stored as starch; used in respiration to release energy.
What are the raw materials for photosynthesis?
Sunlight, water (from roots), and carbon dioxide (from air).
What is produced as a byproduct of photosynthesis?
Oxygen.
What factors affect the rate of photosynthesis?
Temperature, light intensity, and carbon dioxide concentration.
How does temperature affect photosynthesis?
As temperature increases, the rate of photosynthesis increases to an optimum then decreases.
How is light intensity investigated in photosynthesis?
By moving a plant closer to a light source and recording the oxygen produced.
What happens to the rate of photosynthesis as light intensity increases?
The rate of photosynthesis increases until another factor limits further increase.
How is the effect of carbon dioxide on photosynthesis investigated?
By enclosing the leaf in a transparent bag/jar with sodium hydroxide, which absorbs CO2.
What happens to the rate of photosynthesis as carbon dioxide concentration increases?
The rate of photosynthesis increases until another factor limits the increase.
What are the main structures of a leaf involved in photosynthesis?
Cuticle, upper epidermis, spongy layer, palisade layer, phloem, xylem, and stomata.
What is the function of phloem?
Phloem carries sucrose away for respiration or storage as starch.
What is the function of xylem?
Xylem carries water and minerals.
What are stomata and their function?
Stomata are made of guard cells and can open and close to allow gas exchange in the day and prevent water loss at night.
What is the test for starch in leaves?
- Boil the leaf to kill it. 2. Decolourise using ethanol. 3. Wash to soften. 4. Test with iodine - a blue/black colour shows the presence of starch.
What minerals do plants need for healthy growth?
Nitrates, potassium, and phosphates.
What growth problems are caused by nitrate deficiency?
Poor growth.
What growth problems are caused by potassium deficiency?
Yellowing of leaves.
What growth problems are caused by phosphate deficiency?
Poor root growth.
What is the importance of water in plants?
Water is used in photosynthesis, transport of minerals, and provides support by filling cell vacuoles.
What is transpiration?
Water from the xylem evaporates into air spaces; some water vapor is lost from the stoma.
What factors affect the rate of transpiration?
Temperature, humidity, and wind speed.
