Biology

Photosynthesis in Plants

1,492 Questions

Photosynthesis is the biological process by which plants convert light energy into chemical energy. This page contains practice questions covering essential topics like chlorophyll, light reactions, and the pathways specific to plants. This material is crucial for medical entrance exams and academic assessments.

Chlorophyll and pigmentsLight reactionsCalvin cycleCAM plantsElectron transportPhotosynthesis factors

Photosynthesis in Plants Questions

Multiple choice

Which of the following options correctly represents the conditions required for photosynthesis to occur?

  1. Chlorophyll, oxygen, water, sunlight

  2. Chlorophyll, carbon dioxide, water, sunlight

  3. Chlorophyll, oxygen, carbohydrates, sunlight

  4. Chlorophyll, oxygen, carbohydrates, sunlight, carbon dioxide
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Photosynthesis refers to the formation of organic substances by using inorganic raw materials, like carbon dioxide and water, in the presence of green coloured pigment chlorophyll by using the sun's energy.

Multiple choice

The absence of ___________ will make life impossible on Earth.

  1. photosynthesis

  2. transpiration

  3. respiration

  4. glycolysis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Photosynthesis is the process of formation of food by green plants using inorganic raw materials and plants act as an energy source for all other living organisms. Without the same, neither the plants nor the plant dependents would be able to survive. 

Multiple choice

Spirilloxanthin is found in

  1. red algae

  2. higher plants

  3. purple bacteria

  4. iron bacteria
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Photosynthetic purple bacteria have spirilloxanthin as the photosynthetic pigment.

Multiple choice

Assertion (A): Of the wide range of wavelengths in the electromagnetic spectrum, plants can use only visible light for photosynthesis. Reasoning(R): About 48% of the energy in solar radiation reaching plants is in the form of ultraviolet and infrared light and these are not used in photosynthesis.

  1. Both Assertion and Reasoning are true and R is the correct explanation of A.

  2. Both Assertion and Reasoning are true and R is not the correct explanation of A.

  3. A is true and R is false.

  4. Both A and R are false.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Of the wide range of wavelengths in the electromagnetic spectrum, plants can use only visible light for photosynthesis.About 48% of the energy in solar radiation reaching plants is in the form of ultraviolet and infrared light and these are not used in photosynthesis.

Multiple choice

Which of the following herbicides act by interfering in light reaction of photosynthesis?

  1. 2,4-Dichlorophenoxyacetic acid
  2. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea
  3. N-(phosphonomethyl)glycine
  4. 1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine

  1. 1 and 2

  2. 1 and 3

  3. 1 and 4

  4. 2 and 3

  5. 2 and 4
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Two major classes of herbicides that block photosynthetic electron flow are derivatives of urea and triazine herbicides. These herbicides interfere in PS II with binding of plastoquinone (Q) and thus, blocks the transfer of electrons to plastoquinone and also blocks electron transport between PS II and PS I. Examples: Urea derivatives: 3-(4-chlorophenyl)-1-methoxy-1-methylurea and 3-(3,4-Dichlorophenyl)-1,1-dimethylurea Triazine derivatives: 6-Chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine and 1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine.

Multiple choice

Which of the following statements are correct regarding Photosystem I.

  1. Photosystem I occurs in outer surface of thylakoids.
  2. Reaction centre of Photosystem is P680.
  3. It participates in both cyclic as well as noncyclic photophosphorylation.
  4. Molecular oxygen is evolved as a result of photodissociation of water.

  1. 1 and 2

  2. 1 and 3

  3. 1 and 4

  4. 2 and 3

  5. 2 and 4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

PS I lies in the outer surface of thylakoids. PS I participates in both cyclic as well as noncyclic photophosphorylation.

Multiple choice

Which among the following statements about photosynthesis are correct?

  1. Best photosynthesis takes place in violet light.
  2. Quantum yield of photosynthesis is 0.125.
  3. Energy conversion efficiency of photosynthesis is 66%.
  4. 90% of the total photosynthesis in the world is carried out by marine algae.

  1. 1 and 2

  2. 1 and 3

  3. 1 and 4

  4. 2 and 3

  5. 2 and 4
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Quantum yield of photosynthesis is 0.125. 90% of the total photosynthesis in the world is carried out by marine algae.