Biology · Chapter 5 of 19

Plant Physiology: Photosynthesis, Respiration & Nutrition: BPSC & UPPCS Prelims PYQs

19 previous-year questions on Plant Physiology: Photosynthesis, Respiration & Nutrition. Each one opens to its answer and explanation.

1. 1. 71st BPSC Prelims 2025

   In mycorrhizal association, the advantage of plant is:

   1. AProtection
   2. BFood
   3. C(a) and (b) both
   4. DIncreased mineral absorption and diseases protection
   Answer and explanation →

2. 2. 70th BPSC Prelims 2024

   Which component of fertilizer is used for stimulating early growth purpose?

   1. APotassium
   2. BNitrogen
   3. COxygen
   4. DPhosphorus
   Answer and explanation →

3. 3. 70th BPSC Prelims 2024

   For which of the following is chlorophyll used in photosynthesis?

   1. AReduction of CO₂
   2. BBreaking down water molecules
   3. CNo function
   4. DAbsorbing light
   Answer and explanation →

4. 4. 70th BPSC Prelims 2024

   Actual site of dark reaction in photosynthesis inside chloroplast is

   1. AGranum
   2. BGrana Lamella
   3. CStroma
   4. DNone of the above
   Answer and explanation →

5. 5. 68th BPSC Prelims 2023

   The stomata open or close due to change in the

   1. Aposition of nucleus in cells
   2. Bprotein composition of cells
   3. Camount of water in cells
   4. DMore than one of the above
   5. ENone of the above
   Answer and explanation →

6. 6. 68th BPSC Prelims 2023

   Chlorophyll absorbs _________ wavelengths of the sunlight.

   1. Ared and blue
   2. Bgreen and blue
   3. Cgreen and red
   4. DMore than one of the above
   5. ENone of the above
   Answer and explanation →

7. 7. 68th BPSC Prelims 2023

   Water reaches great heights in trees because of suction pull caused by

   1. Aevaporation
   2. Babsorption
   3. Ctranspiration
   4. DMore than one of the above
   5. ENone of the above
   Answer and explanation →

8. 8. 67th BPSC Prelims 2022

   Plants receive their nutrients mainly from

   1. Aatmosphere
   2. Blight
   3. Csoil
   4. Dchlorophyll
   5. ENone of the above/More than one of the above
   Answer and explanation →

9. 9. 67th BPSC Prelims 2022

   Water passes from the soil into the roots by a physical process called

   1. Adiffusion
   2. Btranspiration
   3. Cabsorption
   4. Dosmosis
   5. ENone of the above/More than one of the above
   Answer and explanation →

10. 10. 67th BPSC Prelims 2022

    In the nighttime, it is advised not to sleep under trees because

    1. Athey liberate less amount of oxygen
    2. Bthey liberate harmful gases at night
    3. Cthey liberate carbon dioxide
    4. Dthey liberate carbon monoxide
    5. ENone of the above/More than one of the above
    Answer and explanation →

11. 11. 67th BPSC Prelims 2022

    Insectivorous plants grow in soil deficient in

    1. Awater
    2. Bmagnesium
    3. Cnitrogen
    4. Dcalcium
    5. ENone of the above/More than one of the above
    Answer and explanation →

12. 12. UPPSC Prelims 2021

    Fruits stored in a cold chamber exhibit longer storage life, because

    1. AExposure to sunlight is prevented
    2. BConcentration of CO2 in environment is increased
    3. CRate of respiration decreases
    4. DThere is an increase in humidity
    Answer and explanation →

13. 13. UPPSC Prelims 2021

    After cutting cucumber, if salt is added, then water comes out due to

    1. AActive transport
    2. BPassive transport
    3. COsmosis
    4. DDiffusion
    Answer and explanation →

14. 14. 65th BPSC Prelims 2019

    The by-product of photosynthesis is

    1. ACO2
    2. BO2
    3. Cenergy
    4. DSugar
    5. ENone of the above/More than one of the above
    Answer and explanation →

15. 15. UPPSC Prelims 2017

    Which one of the following is not correctly matched?

    1. ABlue green algae - Paddy
    2. BRhizobium leguminosarum - Pea
    3. CAzotobacter - Wheat
    4. DAzolla - Maize
    Answer and explanation →

16. 16. UPPSC Prelims 2016

    The plants receive Nitrogen in form of

    1. ANitric oxide
    2. BNitrate
    3. CAmmonia
    4. DNitride
    Answer and explanation →

17. 17. UPPSC Prelims 2015

    Which one of the following is a plant hormone?

    1. AInsulin
    2. BThyroxin
    3. CEstrogen
    4. DCytokinin
    Answer and explanation →

18. 18. UPPSC Prelims 2013

    Photosynthesis using the invisible part of the sunlight is done by some

    1. ATrees
    2. BAlgae
    3. CBacteria
    4. DFungi
    Answer and explanation →

19. 19. UPPSC Prelims 2012

    Chlorophyll contains

    1. AIron
    2. BCopper
    3. CMagnesium
    4. DManganese
    Answer and explanation →