Section 3 - Plant Nutrition and Transport Flashcards
Where does photosynthesis take place? (1)
Chloroplasts
What pigment do chloroplasts contain? (1)
Chlorophyll
What does chlorophyll do? (2)
- Absorbs sunlight
- Uses its energy for photosyenthesis
Word equation for photosynthesis? (2)
carbon dioxide + water —> glucose + oxygen
Symbol equation for photosynthesis? (2)
6CO2 + 6H20 —> C6H12O6 + 6O2
Label the parts {9)
1 - Waxy Cuticle
2 - Upper Epidermis
3 - Palisade
4 - Spongy Mesophyll
5 - Xylem
6 - Phloem
7 - Lower Epidermis
8 - Guard Cells
9 - Stoma
Why are leaves broad? (1)
- Large surface area exposed to light
Where are most chloroplasts found in a leaf and why? (3)
- Palisade layer
- So they are near the top of the leaf
- To get the most light
How is the upper epidermis adapted for efficent photosyenthesis (2)
- It is transparent
- So light can pass through it to the palisade layer
Why do leaves have a network of vascular bundles (4)
- These are the transport vessels xylem and phloem
- They deliver water and other nutriets to every part of the leaf
- They take away the glucose produced by photosyenthesis
- Help to support the leaf structure
What is the role of the waxy cuticle (1)
reduces water loss by evaporation
What are stomata and how do they make gas exchange/photosyenthesis more efficent (2)
- Stomata are little holes
- Let CO2 diffuse directly into the leaf
Name 3 factors affecting a plant’s rate of photosyenthesis (3)
- Light
- Amount of CO2
- Temperature of surrondings
Why does not enough light slow down the rate of photosyenthesis (3)
- Chlorophyll uses light energy to perform photosyenthesis
- It can only do it as quickly as the light energy is arriving
- If light intensity is increased, rate of photosyenthesis will steadily increase, up to a point
Why does too little carbon dioxide slow down photosyenthesis (2)
- Because it is a raw material needed for photosyenthesis
- Increasing conc of CO2 will increase rate of photosyenthesis up to a point
Why does this curve flatten out (2)
- Shows the amount of CO2 is not the limiting factor affecting photosyenthesis
- Limiting factor is temperature or light intensity or both
Describe the graph; how temperature affects rate of photosyenthesis (3)
- As the temperature increases, so does the rate of photosyenthesis, up to a point
- If the tempeature goes above roughly 45 degrees, enzymes will denature
- This means the rate of photosyenthesis rapidly decreases
Describe how to test a leaf for Starch? (5)
- Kill it by dunking it in boiling water (hold with tweezers)
- Put leaf in a boiling tube with ethanol
- Heat the tube in a water bath (gets rid of chlorophyll)
- Rinse the leaf in cold water and add a few drops of iodine
- If starch is present, leaf will go blue-black