Flashcards in Plant Nutrition - Part 2 (T2) Deck (12):
Describe photosynthesis in three short points..
- converts carbon dioxide and water into glucose and oxygen
- requires light, which is absorbed by chlorophyll
- takes place in organelles called chloroplasts
From where do plants absorb the water and carbon dioxide needed for photosynthesis?
Plants absorb water through their roots and carbon dioxide through the stomata in their leaves.
What happened to the glucose and oxygen produced by photosynthesis?
- some glucose is used for respiration and some is converted to starch for storage.
- oxygen is released as a by-product.
What part of the plant carries out photosynthesis?
Any green part of a plant can photosynthesise but the main organ of photosynthesis is the leaf.
For photosynthesis to take place efficiently what five things are essential?
- a large surface area for absorption of light
- chloroplasts and chlorophyll
- carbon dioxide
- a transport system
Briefly, how is a leaf adapted to carry out photosynthesis?
- thin and flat
- usually supported by a stalk which enables the leaf to be angled towards light
- contains layers of cells with specific functions to enable efficient photosynthesis
What is the chemical equation for photosynthesis?
6CO2 + 6H2O -> C6H12O6 + 6O2
Describe the three main factors that limit the rate of photosynthesis..
- photosynthesis decreases at low light levels and does not take place at all in the dark
- a plant cannot photosynthesise if there is not enough CO2
- if it gets too cold or hot, the rate of photosynthesis will decrease
Give two examples of how seasons affect plant growth..
- in winter, the lawn doesn't grow due to lack of light and heat
- in summer, the growth slows due to lack of rain
How can you overcome the limiting factors of photosynthesis?
- lights can be used to simulate daylight.
- heating a greenhouse, especially if gas or paraffin heaters are used as they produce carbon dioxide as a by-product.
What is produced by plants during photosynthesis as a waste product?