Nutition In Plants

Question 1

Equation of photosynthesis

Answer 1

6CO2 + 12H2O—(light energy+chlorophyll)—>C6H12O6 + 6O2 +6H2O

Question 2

What are the limiting factors in photosynthesis?

Answer 2

1. light intensity
2. Concentration of CO2
3. Temperature

Question 3

How is the leaf adapted for photosynthesis?

Answer 3

1. Petiole(leaf stalk)—>holds the leaf in position to absorb maximum light energy.
2. Thin board lamina—>provides short diffusion distance + large surface area for maximum absorption of light
3. Waxy cuticle on upper and lower epidermis—>reduces water loss through evaporation + transparent for light to enter
4. Stomata in the lower epidermis—>diffusion of gases
5. More chloroplast in the palisade mesophyll—>more light energy can be absorbed near the leaf surface
6. Numerous large intercellular air spaces—>rapid diffusion of gases

Question 4

How does CO2 enter the leaf?

Answer 4

1. In the daylight—>photosynthesis—>CO2 in the leaf is rapidly used up—>CO2 concentration in the leaf is lower than CO2 concentration in the atmosphere—> atmospheric CO2 diffuses into the air spaces in the leaf via the stomata.
2. The surfaces of the mesophyll cells are always covered with a thin film of moisture—>CO2 can dissolve in it
3. The dissolved CO2 then diffuses into surrounding cells

Question 5

What happens to glucose that is formed during photosynthesis?

Answer 5

1. Converted into sucrose then transported to other parts of the plant
2. Excess glucose is stored as starch