Top 25+ Photosynthesis in Higher Plants - Biology Questions and Answers For NEET 2024 Exam Preparation

Q1. For the synthesis of one glucose molecule the Calvin cycle operates for

1. 2 times
2. 6 times
3. 4 times
4. 8 times.

Answer: (b)

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Q2. Identify A to D in the given figure.

1. A– Light, B– Electron transport system, C– $e^{–}$ acceptor, D– Chlorophyll P700
2. A– $e^{–}$ acceptor, B– Light, C– Chlorophyll P700, D– Electron transport system
3. A– Electron transport system, B– $e^{–}$ acceptor, C– Chlorophyll P700, D– Light
4. A– Chlorophyll P700, B– Electron transport system, C– Light, D– $e^{–}$ acceptor

Answer: (a)

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Q3. Primary $CO_2$ acceptor in $C_4$ plant occurs in

1. Outer layer cells of bundle sheath
2. Inner layer cells of bundle sheath
3. Mesophyll cells
4. None of these

Answer: (c)

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Q4. A process that makes more important difference between $C_3$ and $C_4$ plants is

1. Glycolysis
2. Transpiration
3. Photosynthesis
4. Photorespiration

Answer: (d)

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Q5. Photo-oxidation of chlorophyll is called

1. Chlorosis
2. Intensification
3. Solarization
4. Defoliation

Answer: (c)

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Q6. Which of the following is incorrect about the experiment performed by T. W. Engelmann?

1. Suspension of aerobic bacteria is used.
2. Cladophora (a green algae) is used.
3. Bacteria accumulated mainly in the region of orange and green part of the light spectrum.
4. Prism was used to split light into its spectral component.

Answer: (c)

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Q7. Suspension of isolated thylakoids in culture medium containing $CO_2$ and $H_2$O does not produce hexose due to absence of

1. ATP
2. Proteins
3. Enzyme
4. Hill reagent

Answer: (c)

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Q8. In a crop field a weedicide is used to remove weeds in order to increase the yield. But the effect of this weedicide is that, it blocks electron transport from photosystem II to photosystem I. This will result in

1. failure of ATP synthesis.
2. enhancement of dark reaction.
3. lack of reduction of $NADP^{+}$ .
4. both (a) and (c)

Answer: (d)

During the electron transport from photosystem II to photosystem I, ATP is synthesized and $NADP^{+}$ is reduced to NADPH. So, the blockage of electron transport will stop ATP synthesis and the reduction of $NADP^{+}$ to NADPH.

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Q9. How many types of photosynthetic cells occur in $C_4$ plant?

1. Two types
2. One type
3. Four types
4. Eight types

Answer: (a)

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Q10. Which technique has helped in investigation of Calvin cycle?

1. X-ray crystallography
2. Radioactive isotope technique
3. X-ray technique
4. Intermittent light

Answer: (b)

By employing $^14 C$ labelled carbon dioxide $^14CO_2$ in photosynthesis and observing the appearance of characteristic radiations in different reaction intermediates and product in different experiments.

Calvin and his co-workers were able to formulate the complete metabolic path of carbon assimilation in the form of cycle which is called as Calvin cycle.

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Q11. $NADP^{+}$ is reduced to NADPH in

1. PS I
2. Calvin cycle
3. PS II
4. noncyclic photophosphorylation.

Answer: (d)

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Q12. Dark reactions of photosynthesis occur in

1. granal thylakoid membranes
2. stroma outside photosynthetic lamellae
3. stromal lamella membranes
4. periplastidial space.

Answer: (b)

The dark reactions of photosynthesis are purely enzymatic and slower than the primary photochemical reaction. They take place in stroma portion of the chloroplast and independent of light, i.e., they can occur either in presence or in absence of light provided that assimilatory power is available.

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Q13. A photosynthesising plant is releasing ¹⁸O more than the normal. The plant must have been supplied with

1. O₃
2. CO₂ with ¹⁸O
3. H₂O with ¹⁸O
4. C₆ H₁₂ O₆ with ¹⁸ O.

Answer: (c)

Water molecule breaks up into hydrogen and oxygen in the illuminated chloroplasts. This is called photolysis of water. If a photosynthesising plant is releasing $^{18} O$ more than the normal, the plant must have been supplied with $H_2 O$ with $^{18} O$.

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Q14. In photosynthesis energy from light reaction to dark reaction is transferred in the form of

1. ADP
2. RuDP
3. ATP
4. chlorophyll.

Answer: (c)

Photosynthesis consists of light dependent phase and light independent phase or dark reaction. Light dependent phase occurs in grana fraction of chloroplast. It involves cyclic and non cyclic photophosphorylation where assimilatory powers (ATP and $NADPH_2$ ) are produced.

In dark reaction, which occurs in stroma fraction of chloroplast, actual reduction of $CO_2$ to carbohydrates takes place using the assimilatory powers (ATP and $NADPH_2$ ) produced in the light dependent phase. It needs 18 ATP and 12 $NADPH_2$ molecules to produce one molecule of glucose.

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Q15. Chlorophyll a occurs in

1. all photosynthetic autotrophs
2. all oxygen liberating autotrophs
3. in all higher plants
4. all plants except fungi.

Answer: (b)

Chlorophyll-a occur in all photo- synthesizing plants except bacteria. Chlorophyll-a is the only one common to all organisms that possess chlorophyll (the only one in blue green algae) and is believed to be specifically required. In a few photosynthetic bacteria other kinds of chlorophyll, bacteriochlorophylls, occur.

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Q16. In kranz anatomy, the bundle sheath cells have

1. thin walls, many intercellular spaces and no chloroplasts
2. thin walls, no intercellular spaces and several chloroplasts
3. thick walls, no intercellular spaces and large number of chloroplasts
4. thick walls, many intercellular spaces and few chloroplasts.

Answer: (c)

The $C_4$ plants are adapted to dry tropical regions and have greater productivity of biomass. They have special type of leaf anatomy known as Kranz anatomy.

In this type of anatomy the bundle sheath cells form several layers around the vascular bundles; they are characterised by having a large number of chloroplasts, thick walls impervious to gaseous exchange and no intercellular spaces.

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Q17. Oxysomes or $F_0 – F_1$ particles occur on

1. thylakoids
2. inner mitochondrial membrane
3. mitochondrial surface
4. chloroplast surface

Answer: (b)

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Q18. $C_{4}$ -cycle was discovered by

1. Hatch and Slack
2. Hill
3. Calvin
4. Arnon

Answer: (a)

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Q19. The total requirement of ATP & NADPH for each molecule of $CO_{2}$ fixed & reduced in photosynthesis in the Calvin cycle is

1. 2 ATP & 3 NADPH
2. 2 ATP & 2 NADPH
3. 3 ATP & 2 NADPH
4. 4 ATP & 3 NADPH

Answer: (c)

For every $CO_{2}$ molecule entering the Calvin cycle, 3 molecules of ATP and 2 molecules of NADPH are required.

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Q20. PGA as the first $CO_2$ fixation product was discovered in the photosynthesis of

1. Gymnosperm
2. Bryophyte
3. Angiosperm
4. Alga

Answer: (d)

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Q21. Which of the following statements concerning the Calvin-Benson cycle are false?

1. Carbon dioxide is assimilated into sugars.
2. Light energy is not required for the cycle to proceed.
3. Ribulose 1, 5-bisphosphate (RuBP) is regenerated.
4. None of the above

Answer: (b)

Light energy is required for the Calvin-Benson cycle to proceed. ATP synthesis is dependent on light energy and the Calvin-Benson cycle is dependent on ATP.

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Q22. By looking at which internal structure of a plant can you tell whether a plant is $C_{3}$ or $C_{4}$ ?

1. Distribution of mesophyll cells
2. Kranz anatomy
3. Bundle sheath cells only
4. Both (a) and (b)

Answer: (d)

$C_{4}$ plants possess Kranz type of leaf anatomy. The mesophyll is undifferentiated and its cells occur in concentric layers around vascular bundles.

$C_{4}$ plants possess dimorphic chloroplasts. While in $C_{3}$ plants leaf anatomy is not of Kranz type. Only one type of chloroplasts are found.

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Q23. CAM helps the plants in

1. Conserving water
2. Disease resistance
3. Secondary growth
4. Reproduction

Answer: (a)

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Q24. Plants adapted to low light intensity have

1. larger photosynthetic unit size than the sun plants
2. more extended root system
3. higher rate of $CO_2$ fixation than the sun plants
4. leaves modified to spines.

Answer: (a)

To absorb more sunlight (quantitatively), the plants growing in low light conditions have larger photosynthetic unit size. It means that they have more number of chlorophyll molecules per reaction center. to trap more light energy available to them.

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Q25. Reduction process of Calvin cycle requires how many ATP and NADPH for the reduction of one molecule of $CO_2$ ?

1. 2 mole ATP and 2 mole NADPH
2. 2 mole ATP and 3 mole NADPH
3. 1 mole ATP and 2 mole NADPH
4. 3 mole ATP and 2 mole NADPH

Answer: (a)

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