Factors Affecting Photosynthesis

Q.

With reference to factors affecting the rate of photosynthesis which of the following statements is not correct?

1. Light saturation for CO2 fixation occurs at 10% of full sunlight?

2. Increasing atmospheric CO2 concentration up to 0.05% can enhance CO2 fixation rate?

3. C3 plants respond to higher temperatures with enhanced photosynthesis while C4 plants have much lower temperature optimum?

4. Tomato is a greenhouse crop that can be grown in CO₂ – enriched atmosphere for a higher yield?

Q.

The product of photosynthesis is not a protein. State whether the statement is True or False. Justify your answer.

1. True
2. False

Q.

Figure 13.10 shows the effect of light on the rate of photosynthesis. Based on the graph, answer the following questions:

(a) At which point/s (A, B or C) in the curve is light a limiting factor?

(b) What could be the limiting factor/s in region A?

(c) What do C and D represent on the curve?

Q. Which of the following is a major limiting factor for photosynthesis in $C_3$ plants?

1. Water
2. Carbon dioxide
3. Sunlight
4. Humidity

Q. Which of the following is an internal factor that influences photosynthesis?

1. Temperature
2. Availability of sunlight
3. Availability of water
4. Amount of chlorophyll

Q. Which of the following is not a limiting factor for photosynthesis?

1. Carbon dioxide
2. Light
3. Chlorophyll
4. Oxygen

Q.

The process of loss of water by a plant through leaves is called

1. Evaporation

2. Condensation

3. Photosynthesis

4. Transpiration

Q. How can we explain that light dependent and independent reaction dependent on each other?

Q.

How do limiting factors affect the rate of photosynthesis?

Q. Plants show light saturation effect at _______ of full sunlight.

1. 50%
2. 70%
3. 100%
4. 10%

Q. Rate of photosynthesis is dependent on ____________

1. light quality
2. light intensity
3. duration of light
4. All of the above

Q. What is the optimum temperature required for $C_3$ plants?

1. $30-{40}^{\circ }C$
2. $20-{25}^{\circ }C$
3. Above ${40}^{\circ }C$
4. Above ${25}^{\circ }C$

Q.

Question 36
Why does the rate of photosynthesis decrease at higher temperatures?

Q. When the intensity of light is gradually increased from low to high the rate of photosynthesis ________________________.

1. increases
2. decreases
3. increases and then decreases
4. decreases and then increases

Q. For the given reaction P4+5O2 _ p4O10 if 31g of p4 is reacted with excess of oxygen the parentage yield is 60% the amount of product formed is

Q.

Most plants are green in color because

1. The atmosphere filters out all the colors of the visible light spectrum except green

2. Green light is the most effective wavelength region of the visible spectrum in sunlight for photosynthesis

3. Chlorophyll is least effective in absorbing green light

4. Green light is reflected by the green leaves of the plant

Q.

What are the 2 parts of the photosystem?

Q. Which of the following have yellow colour pigment ?
a. Chlorophyll a
b. Xanthophylls
c. Carotene
d.chlorophyll b

Q.

Select the correct statements from the following

(A) At high light intensities, plants show increase in rate of photosynthesis.

(B) Tropical plants have higher temperature optimum than the plants adapted to temperate climates.

(C) The effect of water as a factor is more through its effect on the plant, rather than directly on photosynthesis

1. A & C

2. B & C

3. A, B & C

4. A & B

Q.

Why do leaves turn red and shed off during the autumn season?

Q.

What are the main physiological parameters that influence plant growth?

Q. When the level of $C{O}_2$ used in photosynthesis is equal to the amount of $C{O}_2$ released by respiration and photorespiration it is called ___________.

1. extinction point
2. $C{O}_2$ saturation point
3. $C{O}_2$ compensation point
4. $C{O}_2$ fixation

Q.

The products of photosynthesis are glucose and oxygen

1. True
2. False

Q. Under high light intensity the concentration of $C{O}_2$ is 420 ppm. Which of the following statements is correct in such a scenario?

1. $C_3$ plants will die due to excess concentration of $C{O}_2$
2. $C_3$ plants will show an increase in productivity
3. $C_3$ plants will show a decrease in the rate of photosynthesis
4. $C_3$ plants will show a decrease in productivity

Q. The rate of photosynthesis is highest in ___________.

1. green light
2. yellow light
3. red light
4. blue light

Q. When the level of $C{O}_2$ used in photosynthesis is equal to the amount of $C{O}_2$ released by respiration and photorespiration it is called ___________.

1. extinction point
2. $C{O}_2$ saturation point
3. $C{O}_2$ compensation point
4. $C{O}_2$ fixation

Q.

Grana produce all the enzymes of dark reaction.

1. True
2. False

Q. During monsoon, the rice crops of eastern states of India show lesser yield due to _________ being the limiting factor.

1. $C{O}_2$
2. Light
3. Temperature
4. Water

Q.

What is maximum absorption by chlorophyll a at regions are indicative of?

Q.

Do C4 plants produce oxygen?