Biology MCQs: Plant Physiology


Multiple Choice Questions on Plant Physiology with answers. Topics covered are Plant water relations, Mineral Nutrition, Biological Nitrogen Fixation, Transport in Plants, Photosynthesis (Set I/ Set II), Respiration (Set I/ Set II), Plant Hormones- Auxins, Plant Hormones -Cytokinins, Plant Hormones- Gibberellins, Plant Hormones – Abscisic acid (ABA), Plant Hormones- Ethylene, Plant Hormones-Vernalin, Morphatin,Bsassinosteroids. NCERT Textbook fully covered. Essential topic for all PMT Exam.

MCQ on Plant Physiology – Plant Water Relations

1. The water readily available to plants for absorption by roots is
a) Gravitational water
b) Capillary water
c) Rain water
d) Hygroscopic water

2. The water potential of pure water at atmospheric pressure is
a) -2.3 bar
b) +2.3 bar
c) Zero bar
d) One bar

3. Loss of water from the stomata of leaves are known as
a) Guttation
b) Exudation
c) Transpiration
d) Evaporation

4. During rainy season wooden doors are difficult to open or closure because of
a) Plasmolysis
b) Imbibition
c) Osmosis
d) Diffusion

5. Plasmolysis occurs due to
a) Absorption
b) Osmosis
c) Endoosmosis
d) Exosmosis

6. The marine animals that kept in fresh water burst. It shows the process of
a) Exosmosis
b) Endoosmosis
c) Plasmolysis
d) Deplasmolysis

7. Cooling of plants is caused by
a) Guttaion
b) Photorespiration
c) Transpiration
d) Assimilation

8. Active uptake of minerals by roots mainly depends on the
a) Availability of oxygen
b) Temperature
c) Light
d) Availability of CO2

9. The hormone which signals the closure of stomata is
a) Auxins
b) Cytokinine
c) Gibberelline
d) Abscisic acid

10. Water absorption takes place through
a) Lateral roots
b) Root cap
c) Root hairs
d) Tap root

11. Which of the following is an anti-transpirant
a) PMA
b) PAN
c) IAA
d) AUG

12. What is the action spectrum of transpiration?
a) Orange and red
b) Green and ultraviolet
c) Blue and red
d) None of these

13. Which one of the following is used for measuring the rate of transpiration?
a) Porometer
b) Osmometer
c) Moll’s experiment
d) Potometer

14. Transpiration is least in
a) High atmospheric humidity
b) good soil moisture
c) high wind velocity
d) dry environment

15. Stomata open at night and close during day time in
a) Xerophytes
b) Mesophytes
c) Succulents
d) Hydrophytes

1- b
2- c

  1. aaryan 3 months ago

    thanks that was helpful

  2. Shabir Ahmad magray 2 years ago

    Please answer this question
    Q.Inside the root nodules the rhizobia change their form to cells called
    1.rhizoids ,2.rhizomoids,3.bacteriods,4.bacteriomoids

  3. Peer Aamir 2 years ago

    Absolutely awesome.. Thanks

  4. SOURABH DENDOR 3 years ago

    Amazing collection very useful I like it very very much.

  5. BHAVYA 4 years ago

    Thank you very much……extreamly useful for competitive exam preparation….

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