Action Spectrum

Q.

Which light range is most effective in photosynthesis?

Q. At which wavelength (colour of light), maximum photosynthesis in plants is observed?

1. Blue and red
2. Blue and green
3. Red and green
4. Red and yellow

Q.

Why do plants absorb blue and red light?

Q.

Question 51
What can we conclude from the statement that the action and absorption spectrum of photosynthesis overlap? At which wavelength do they show peaks?

Q. The most effective wavelength of light participating in photosynthesis is

1. 450-520 nm
2. 520-560 nm
3. 700-760 nm
4. 660-700 nm

Q.

Question 04
Which light range is most effective in photosynthesis?
(a) Blue (b) Gree (c) Red (d) Violet

Q. Of the total incident solar radiation the proportion of PAR is:

1. More than 80%
2. About 60%
3. About 70%
4. Less than 50%

Q.

Question 53
In the figure given below, the black line (upper) indicates action spectrum for photosynthesis and the lighter line (lower) indicates the absorption spectrum of chlorophyll-a, answer the following

(a) What does the action spectrum indicate? How can we plot an action spectrum? Explain with an example.

(b) How can we derive an absorption spectrum for any substance?

(c) If chlorophyll-a is responsible for light reaction of photosynthesis, why do the action spectrum and absorption spectrum not overlap?

Q. Label a, b, and c respectively.

1. Chlorophyll a, chlorophyll b, carotenoids
2. Chlorophyll a, chlorophyll b, xanthophylls
3. Chlorophyll a, xanthophylls, carotenoids
4. Chlorophyll a, xanthophylls, chlorophyll b

Q.

Question 03
Which range of wavelength (in nm) is called Photosynthetically Active Radiation (PAR)?
(a) 100-390 (b) 390-430 (c) 400-700 (d) 760-100, 00

Q.

What conclusion was drawn from the red drop and enhancement experiments in the light reaction of photosynthesis

1. Two photosystems are present

2. One photosystem is present

3. Two photosystems are present which work at different wavelengths

4. Two photosystems are present which work at some wavelength

Q. The evidence of existence of two photosystems in light reactions of photosynthesis was given by

1. Arnon
2. Hill
3. Emerson
4. Englemann

Q. The leaves of a plant appear green because these

1. Absorb green light
2. Absorb and reflect green light
3. Reflect green light
4. Neither absorb nor reflect green light

Q. Green light has a wavelength of

1. 400 – 450 nm
2. 500 − 580 nm
3. 660 – 720 nm
4. 720 − 800 nm

Q. What is the percentage of photosynthetically active radiation(PAR), in the incident solar radiation.

1. 50%
2. 100%
3. 1 - 5%
4. 2 - 10%

Q. Determine the wavelength at which chlorophyll a shows maximum absorption? Can you determine the wavelength (colour of light) at which chlorophyll a shows the maximum absorption? Does it show another absorption peak at any other wavelengths too? if yes, which one?

Q.

What is the percentage of photosynthetically active radiation (PAR), in the incident solar radiation.

(a) 100%

(b) 50 %

(c) 1-5%

(d) 2-10%

Q.

In which of the following light is the rate of photosynthesis maximum?

1. Green

2. White

3. Red

4. Blue

Q. Green light has a wavelength of

1. 400 – 450 nm
2. 500 − 580 nm
3. 660 – 720 nm
4. 720 − 800 nm

Q. The photosynthetic pigment which appears bright or blue-green colour in the chromatogram is/are:

1. Carotenoids
   
2. Xanthophylls
3. Chlorophyll b
4. Chlorophyll a

Q. Of the total incident solar radiation the proportion of PAR is

1. More than 80%
2. About 70%
3. About 60%
4. Less then 50%

Q. Of the total incident solar radiation the proportion of PAR is:

1. More than 80%
2. About 70%
3. About 60%
4. Less than 50%

Q. Blue and red light are equally effective in photosynthesis but blue light is less efficient because

1. It is fluorescent.
2. It has lesser wavelength than red light.
3. Most of its energy is wasted in form of infra red radiation.
4. It cannot bring photolysis of water and release of oxygen alone.

Q. The most effective wavelength of light participating in photosynthesis is

1. 450-520 nm
2. 700-760 nm
3. 660-700 nm
4. 520-560 nm

Q. The leaves of a plant appear green because these

1. Absorb and reflect green light
2. Absorb green light
3. Reflect green light
4. Neither absorb nor reflect green light

Q. Who demonstrated that photosynthesis is essentially a light-dependent reaction?

1. T.W. Engelmann
2. Julius von Sachs
3. Joseph Priestley
4. Cornelius van Niel

Q. Which colour of light gives maximum absorption peak of chlorophyll a

1. Red
2. Blue
3. Green
4. Yellow

Q. Photosynthetically Active Radiation (PAR) has the following range of wavelengths

1. 340-450 nm
2. 400-700 nm
3. 500-600 nm
4. 450-950 nm

Q. The leaves of a plant appear green because these

1. Absorb and reflect green light
2. Absorb green light
3. Reflect green light
4. Neither absorb nor reflect green light

Q. Photosynthetically Active Radiation (PAR) has the following range of wavelengths

1. 340-450 nm
2. 500-600 nm
3. 400-700 nm
4. 450-950 nm