Cornelius Van Niel Experiment

Q. Which helped in confirming that oxygen evolved in photosynthesis comes from water

1. $H_2^{18}O$
   
2. ${}^{14}C{O}_2$
   
3. ${}^{15}N{O}_3$
   
4. ${}^3{H}_{2}O$

Q. Who demonstrated that in purple and green sulphur bacteria when $H_{2}S$ is used as hydrogen donor, sulphur is released instead of oxygen?

1. Julius von Sachs
2. Engelmann
3. Van Niel
4. Jan Ingenhousz

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 of the following organism(s) does not release oxygen as its byproduct during photosynthesis?

1. Cyanobacteria
2. Purple & green sulphur bacteria
3. None of the above
4. (a) and (b)

Q.

1. What does this experiment show?
2. Name the gas that evolved in this process.
3. What is the source of this gas?
4. Name the plant used in this experiment.

Q.

(Answer 10, 11, 12, 13, 14, and 15 on the basis of the following given data)
A Hydrilla plant is kept in a beaker containing water. It is converted with an inverted glass funnel and a test tube. The whole experiment is put in sunlight. It is found that the level of water is coming down and gas accumulates at the upper end of the test tube. The whole experiment is conducted in red, blue, and green light. After some time some amount of sodium bicarbonate is added to the beaker. Will these modifications affect the experiments in any way?

Which is the gas accumulating in the test tube?

1. Carbon dioxide

2. Oxygen

3. Nitrogen

4. Ozone

Q. Who demonstrated that in purple and green sulphur bacteria when $H_{2}S$ is used as hydrogen donor, sulphur is released instead of oxygen?

1. Engelmann
2. Julius von Sachs
3. Van Niel
4. Jan Ingenhousz

Q.
Chlorosis is a common symptom of nitrogen and sulphur deficiency

1. True
2. False

Q. The purple sulphur bacteria use hydrogen sulphide and
release sulphur but not oxygen. Which of the following
agrees with above observation

1. The $H_2$ that reduces $C{O}_2$ comes from $H_{2}S$ that liberates sulphur
2. photosynthesiss does not require chlorophyll
3. Photosynthesis consist of a light and a dark reaction
4. The $H_2$ which reduces $C{O}_2$in photosynthesis comes from $H_{2}O$ that releases $O_2$

Q. Molybdenum is important for

1. Carbon assimilation
2. Cell Division
3. Nitrogen metabolism
4. Plant breeding

Q.

Photoautotrophs lacking chlorophyll $a$ are

Q. Choose the correct answer from the alternatives given.
While visiting a field, a student of botany observed symptoms of chlorosis on some leaves. He inferred it was due to nitrogen deficiency This inference could be correct only if yellowing of leaves occurs first in:

1. young leaves
2. mature leaves
3. mature leaves followed by young leaves
4. young leaves followed by mature leaves

Q. Who, among the following discovered that the oxygen is evolved from water during photosynthesis

1. R. Mayer
2. Ruben
3. Blackman
4. Calvin

Q. Seeds placed deep in the soil do not germinate because they are

1. Unable to get sufficient oxygen
2. Without sufficient food to bring the seedling to the surface
3. Under pressure of overlying soil layers
4. Unable to get light

Q. Which helped in confirming that oxygen evolved in photosynthesis comes from water

1. $H_2^{18}O$
   
2. ${}^{14}C{O}_2$
   
3. ${}^{15}N{O}_3$
   
4. ${}^3{H}_{2}O$

Q. Who, among the following discovered that the oxygen is evolved from water during photosynthesis

1. R. Mayer
2. Ruben
3. Blackman
4. Calvin

Q. What did Engelmam observed from his prism experiments?

1. Bacteria could not be used to detect the sites of $O_2$ evolution
2. Bacteria accumulated and released excess carbon dioxide in red and blue light
3. Bacteria are accumulated towards red and blue light
4. Bacteria accumulated due to increases in temperature caused by increase in oxygen concentration

Q. How can you prove that carbon dioxide is essential for plants?

Q.

(Answer 10, 11, 12, 13, 14, and 15 based on the following given data)
A Hydrilla plant is kept in a beaker containing water. It is converted with an inverted glass funnel and a test tube. The whole experiment is put in sunlight. It is found that the level of water is coming down and gas accumulates at the upper end of the test tube. The whole experiment is conducted in red, blue, and green light. After some time some amount of sodium bicarbonate is added to the beaker. Will these modifications affect the experiments in any way?

If 50% leaves of Hydrilla are removed, the rate of photosynthesis will be

1. Less, but total photosynthesis will be more

2. Less, and total photosynthesis will also be less

3. More, but total photosynthesis will be less

4. More, but total photosynthesis will also be more

Q. A green plant turns pale, when transferred to prolonged darkness. It represents a phenomenon called as

1. Etiolation
2. Chlorosis
3. Cytorrhisis
4. Paleolation

Q. The early suggestion that oxygen liberated by plants during photosynthesis comes from water was

1. confirmed by the use of heavy water
2. made after the discovery of photorespiration because of Rubisco's sensitivity to oxygen
3. Was proposed by van Niel and later confirmed by experiments using heavy water
4. proposed by van Niel

Q. Q. Which is not true regarding $C_4$ plants?
(l) Adapted to high temperature
(2) Double carboxylation
(3) Require more energy for $C{O}_2$ fixation than $C_3$
(4) Do not produce organic acids

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. Anoxygenic photosynthesis is characteristic of-

1. Chlamydomonas
2. Ulva
3. Rhodospirillum
4. Spirogyra

Q. The model organism that has largely been responsible for making rapid advances in research on photosynthesis is

1. Chlamydomonas
2. Spinach leaf
3. Chlorella
4. Hydrilla

Q. Bacterial photosynthesis involves

1. Both PS-I and PS-II
2. PS-I only
3. None of the above
4. PS-II only
   

Q. Which among the following is used by purple and green sulphur bacteria during photosynthesis?

1. ${\text{H}}_2\text{S}$
2. $\text{HCl}$
3. $\text{HF}$
4. $\text{HBr}$