Question

Describ any six factors that affect the proess of photoy nthesis

Answer 1

Answer:hey mate I know only 3 factor

1. Sunlight

2. Water

3. Temperature

Hope these three doctors will help u in solving your problem

Explanation: please mark me as the brainliest and mark thanks also. Thank u

Answer 2

Answer:

Explanation:

1. light :

• There is a linear relationship between incident light and CO₂ fixation rates at low light intensities.
• At higher light intensities, gradually the rate does not show further increase as other factors become limiting.
• light saturation occurs at 10 per cent of the full sunlight. Hence, except for plants in shade or in dense forests, light is rarely a limiting factor in nature.
• Increase in incident light beyond a point causes the breakdown of chlorophyll and a decrease in photosynthesis.

2. Carbon dioxide :

• Carbon dioxide is the major limiting factor for photosynthesis.

• The concentration of CO2 is very low in the atmosphere (between 0.03 and 0.04 per cent).
• Increase in concentration upto 0.05 per cent can cause an increase in CO2 fixation rates; beyond this the levels can become damaging over longer periods.
• The C3 and C4 plants respond differently to CO2 concentrations.
• At low light conditions neither group responds to high CO2 conditions.
• At high light intensities, both C3 and C4 plants show increase in the rates of photosynthesis.
• the C4 plants show saturation at about 360 µlL­­­­­­-1 while C3 responds to increased CO2 concentration and saturation is seen only beyond 450 µlL­­­­­­-1. Thus, current availability of CO2 levels is limiting to the C3 plants.
• The fact that C3 plants respond to higher CO2 concentration by showing increased rates of photosynthesis leading to higher productivity has been used for some greenhouse crops such as tomatoes and bell pepper.
• They are allowed to grow in carbon dioxide enriched atmosphere that leads to higher yields.

3. Temperature :

• The dark reactions being enzymatic are temperature controlled.
• Though the light reactions are also temperature sensitive they are affected to a much lesser extent.
• The C4 plants respond to higher temperatures and show higher rate of photosynthesis while C3 plants have a much lower temperature optimum.  
• The temperature optimum for photosynthesis of different plants also depends on the habitat that they are adapted to.
• Tropical plants have a higher temperature optimum than the plants adapted to temperate climates.

4. Water :

• Even though water is one of the reactants in the light reaction, the effect of water as a factor is more through its effect on the plant, rather than directly on photosynthesis.
• Water stress causes the stomata to close hence reducing the CO2 availability.
• Besides, water stress also makes leaves wilt, thus, reducing the surface area of the leaves and their metabolic activity as well.
• Photosynthetic process utilizes less than 1 % of the water absorbed by a plant, hence it is rarely a limiting factor in photosynthesis.

5. Chlorophyll :

• Chlorophyll is the most important because light is trapped only by it. There is no photosynthesis in the absence of chlorophyll.
• Increased chlorophyll leads to an increase in photosynthesis.

6. Photosynthetic products :

• With the accumulation of the end products of photosynthesis in mesophyll cells, there is decrease in their photosynthetic rate because concentration of theses products in the cells increases the rate of respiration.