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
  1. Strobilus

  2. Calyptra

  3. Cotyledons

  4. Integuments

  5. Locules

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Two large green hemispherical structures which enclose the embryonic axis are called as the cotyledons. The cotyledons may be one or two in number depending on the type of plant. The cotyledons are important becausetheyt give nutrients during the early development of the plant before starting the process of photosynthesis.  

Multiple choice
  1. phycourobilin

  2. phycoerythrobilin

  3. phycoerythrin

  4. phycocyanobilin

  5. phycocyanin

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Phycocyanobilin is a blue phycobilin, i.e. a tetrapyrrole chromophore found in cyanobacteria and in the chloroplasts of red algae, glaucophytes and some cryptomonads. Phycocyanobilin is present only in the phycobiliproteins allophycocyanin and phycocyanin, of which it is the terminal acceptor of energy.

Multiple choice
  1. Chlorophyll b

  2. Chlorophyll a

  3. Pheophytin

  4. Carotenes

  5. Xanthophylls

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pheophytin is a chemical compound that serves as the first electron carrier intermediate in the electron transfer pathway of photosystem II (PS II) in plants and the photosynthetic reaction center (RC P870) found in purple bacteria.

Multiple choice
  1. Emerson and Arnold - Existence of light and dark reactions in photosynthesis

  2. Engelmann - Chloroplasts as the site of photosynthesis

  3. Hatch and Slack - C3 pathway for CO2 fixation

  4. Ruben and Kamen - Oxygen comes from water in photosynthesis

  5. Peter Mitchell - Chemiosmotic hypothesis of ATP synthesis in light reaction

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In 1966, Hatch and Slack reported the C4 pathway for CO2 fixation in certain tropical plants. In 1954, Melvin Calvin traced the path of carbon in photosynthesis and gave the C3 cycle (now known as Calvin cycle).

Multiple choice
  1. Both P and Q

  2. Both P and S

  3. Both Q and R

  4. Both R and S

  5. Both Q and S

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dark reaction occurs in stroma of chloroplast. Statement Q is true, but statement S is false.

Multiple choice
  1. 'Chlorophyll a'

  2. 'Chlorophyll b'

  3. Carotenoids

  4. Anthocyanins

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carotenoids are very long-chain water-repelling pigments that are synthesized in the plastids of plant cells. These pigments primarily absorb  the blue wavelengths, allowing the longer wavelengths to be scattered and producing the yellow colour.

Multiple choice
  1. photosynthesis

  2. photoreceptors

  3. photolysis

  4. photons

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Photolysis is the light-driven decomposition of water into hydrogen and oxygen, occurring during photosynthesis' light-dependent reactions. Chlorophyll absorbs light energy to split water molecules, releasing electrons for the electron transport chain and oxygen as a byproduct.

Multiple choice
  1. stroma

  2. thylakoids

  3. leaves

  4. none of the above

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The light-independent reactions, also known as the Calvin cycle, occur in the stroma of the chloroplast. The stroma is the fluid-filled space surrounding the thylakoids where CO2 fixation and sugar synthesis take place. Light-dependent reactions occur in the thylakoid membranes.

Multiple choice
  1. nitrogen cycle.

  2. hydraulic cycle.

  3. petrological cycle.

  4. food chain cycle.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

During photosynthesis process, solar energy is being transferred through the food chain. It is being transformed from one chemical form to another. In this process, much of the food energy is lost as metabolic heat.

Multiple choice
  1. 75 - 80%

  2. 25 - 30%

  3. 10 - 15%

  4. 1 - 2%

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Only about 1-2% of the water absorbed by plant roots is actually used in photosynthesis to produce carbohydrates. The remaining 98-99% is lost through transpiration. This water loss is necessary to create the transpiration pull that drives water and mineral absorption from soil, making it essential despite the inefficiency.