Assertion: When simultaneously exposed to light of both red and far red wavelengths, the rate of photosynthesis is far higher than the sum of the red light and far red light photosynthesis rates.
Reason: Two photosystems, processing different wavelengths, cooperate in photosynthesis.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion: A reduction in photorespiration by genetic engineering or because of increasing atmospheric carbon dioxide (due to fossil fuel burning) may not benefit plants as has been proposed.
Reason: Photorespiration may be necessary for the assimilation of nitrate from soil.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Plants photosynthesise during the day, whereas they respire at night.
Reason: Photosynthesis can occur in the presence of sunlight whereas respiration cannot.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

What conclusions can be drawn from the Moll’s half leaf experiment [the given diagram shows the schematic representation of the experiment]?

What can be said after observing the results of the experiment?
I. Negative starch test by the leaf portion present inside the bottle indicates ${\mathrm{CO}}_2$ is necessary for this process.
II. Negative test of starch, which is also shown by the portion of the leaf present in between the split of the split cork is due to the lack of ${\mathrm{CO}}_2$ and light, thus indicating that both of them are essential requirements.

C. B van Niel proved that:
1. Plants produce glucose when they grow.
2. Blue and red light are effective for photosynthesis.
3. It is only the green parts of the plants that could release oxygen.
4. Hydrogen from a suitable oxidizable compound reduces carbon dioxide to carbohydrates.

When do you think the chloroplasts will be aligned with their flat surfaces parallel to the walls of the mesophyll cells?
1. In dark
2. When light intensity is low
3. When light intensity is high
4. They are always aligned parallel to the walls

It can be correctly said about the relation between the absorption spectra of various pigments and the action spectrum of photosynthesis that:

What is true regarding PSI and PSII?
1. PS I works before PS II during the light reaction
2. A single chlorophyll a molecule makes the reaction center in both PS I and PS II
3. The reaction center of PS I is P680 and in PS II is P700
4. LHC is seen in PS I but not in PS II

The electrons needed to replace those removed from PS I are provided by:

Consider the following two statements and choose the correct response from the options given below:
I. Protons and oxygen formed by splitting of water are released in the lumen of thylakoid.
II. PS II is physically located on the inner side of the membrane of the thylakoid.
1. Both I and II are true and II explains I
2. Both I and II are true but II does not explain I
3. I is true and II is false
4. I is false and II is true