Biology

Photosynthesis in Plants

1,508 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 process is most directly driven by light energy?

  1. Creation of a pH gradient by pumping protons across thethylakoid membrane

  2. Carbon fixation in the stroma

  3. Reduction of NADP-molecules

  4. Removal of electrons from chlorophyll molecules

  5. ATP synthesis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Chlorophyll absorb a photon of light molecule, causing the electrons to become excited and move to a higher energylevel.these high energy level can flow along one of two pathways giving cyclic electron flow or noncyclic electron flow

Multiple choice

Which of the following processes converts atmospheric carbon into glucose molecules?

  1. Transpiration

  2. Fossilization

  3. Decomposition

  4. Photosynthesis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Photosynthesis is the process where plants, algae, and some bacteria use sunlight to convert atmospheric carbon dioxide (inorganic carbon) into glucose (organic carbon). This occurs through the Calvin cycle where CO2 is 'fixed' into carbohydrate molecules. Transpiration is water loss, fossilization forms fossils, and decomposition breaks down organic matter.

Multiple choice

What do plants take in during day time?

  1. Take CO2 and give O2

  2. Take O2 and give O2

  3. Take CO2 and give CO2

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During daylight, plants perform photosynthesis, taking in carbon dioxide (CO2) and releasing oxygen (O2) as a byproduct. At night, they primarily respire, taking in O2 and releasing CO2. Options B and C incorrectly state the gas exchanges, and D is wrong because photosynthesis does occur during the day.

Multiple choice

Which of the following occurs both during cyclic and non-cyclic modes of photophosphorylation?

  1. Formation of ATP

  2. Release of O2

  3. Formation of NADPH

  4. Involvement of both PS-I and PS-II
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Both cyclic and non-cyclic photophosphorylation produce ATP. However, only non-cyclic photophosphorylation produces NADPH and releases oxygen (involving both Photosystem I and II). Cyclic photophosphorylation only involves Photosystem I and generates ATP without producing NADPH or oxygen.

Multiple choice

Which of the following statements is/are false about photosynthesis?

  1. It causes absorption of light energy by chlorophyll molecules.

  2. Water molecules are splitted into H2 and O2 atoms.

  3. ATP is formed in this process.

  4. The reaction of CO2 takes place to form carbohydrates.

  5. Options (2) and (4)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 The reaction of CO2 takes place in this process.

Multiple choice

Which gas is released by the plants during photosynthesis ?

  1. Carbon dioxide

  2. Oxygen

  3. Nitrogen

  4. Argon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During photosynthesis, plants take in carbon dioxide and water, and using sunlight energy, produce glucose and release oxygen. The oxygen released comes from the water molecules (H2O), not CO2. This is why plants are called oxygen factories - they replenish atmospheric oxygen.

Multiple choice

Which of the following conditions will increase the rate of photosynthesis?

  1. Adding sodium bicarbonate in water given to plants

  2. Adding boiled and cooled water in plants

  3. Keeping the plant in shaded region

  4. Adding KCN in the water given to plants

  5. Keeping the plant in green light
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

On adding sodium bicarbonate in water, there is an increase in release of carbon dioxide. This in turn increases the rate of photosynthesis.

Multiple choice

Photosynthesis is a/ an

  1. exothermic process

  2. endothermic process

  3. a neutral process

  4. a thermostatic process
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Photosynthesis absorbs light energy to convert CO2 and water into glucose and oxygen. Since energy is absorbed (endothermic) rather than released, this is an endothermic process requiring continuous energy input from sunlight.