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

Sugarcane shows high efficiency of CO2 fixation due to which of the following?

  1. Calvin cycle

  2. Hatch-Slack cycle

  3. TCA cycle

  4. Greater sunlight

  5. -
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The C4 pathway was elucidated by Marshall Davidson Hatch and C. R. Slack in Australia in 1966. It is sometimes called the Hatch-Slack pathway. This pathway is a modification of Calvin cycle and is advantageous to plants that grow in dense stands of tropical vegetation, where the CO2 concentration may be very much reduced.

Multiple choice

In photosynthesis, there is

  1. reduction of H2O

  2. oxidation of H2O

  3. oxidation of CO2

  4. oxidation of NO2

  5. -
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Light reaction takes place in the thylakoid discs where water is oxidised and oxygen is released. The electrons that are freed-up from water are transferred to ATP and NADPH. 

Multiple choice

Cyanobacteria are algae having

  1. blue-green pigment

  2. red pigment

  3. brown pigment

  4. yellow-brown pigment

  5. -
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct Answer: blue-green pigment

Multiple choice

In the process of photosynthesis,

  1. O2 is taken and CO2 is evolved

  2. O2 is taken but CO2 is not evolved

  3. CO2 is taken and O2 is evolved

  4. CO2 is taken and NO2 is evolved

  5. NO2 is evolved

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

Correct Answer: CO2 is taken and O2 is evolved

Multiple choice

Pigment present in cyanobacteria is

  1. r-phycocyanin

  2. r-phycoeythrin

  3. c-phycocyanin

  4. anthocyanin

  5. -
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Phycoerythrin is a red protein-pigment complex from the light-harvesting phycobiliprotein family. It is present in red algae and cryptophytes, accessory to the main chlorophyll pigments. It is responsible for photosynthesis.

Multiple choice

Oxygen is not evolved during photosynthesis of

  1. photosynthetic red algae

  2. photosynthetic green algae

  3. photosynthetic blue-green algae

  4. photosynthetic purple bacteria

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

Purple bacteria or purple photosynthetic bacteria are proteobacteria that are phototrophic. They are capable of producing their own food via photosynthesis. They are pigmented with bacteriochlorophyll a or b, together with various carotenoids, which gives them colours ranging among purple, red, brown and orange. It does not evolve oxygen.

Multiple choice

The first stable product of photosynthesis in C3 plants is

  1. PGAL

  2. RuBP

  3. PGA

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

The C3 cycle is initiated by the enzyme Rubisco that catalyses the carboxylation of the CO2 acceptor molecule ribulose-1,5-bisP (RuBP). It results in the formation of 3-phosphoglyceraldehyde.