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 biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Number of thylakoids in a granum is 

  1. 10-100

  2. 5-10

  3. 100-200

  4. 200-500
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
  • It is a site for light-dependent reactions of photosynthesis. 
  • It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
  • A stack of thylakoid disk is organized to form grana.
  • There are about  10 to 100 thylakoids within a granum and about 40- 60 grana in a plant cell.
  • So, the correct answer is '10-100'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

All types of plastids possess essentially the same structure because they

  1. Perform the same function.

  2. Store food materials like starch, fat and protein.

  3. Occur in aerial parts.

  4. Can transform from one form to another.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plastids are considered as sac-like organelles, generally involved in the formation or storage of food. These are chloroplast, chromoplast and leucoplast and are same in their structure to transform into one another during the requirement.

So the correct option is 'Can transform from one form to another.'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Lipid content of chloroplast is

  1. 20-30%

  2. 5-10%

  3. 4-5%

  4. 1-2%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Plastids are a pigment containing double membrane-bound organelle which is the site of manufacture and storage of chemical compounds.
  • The chloroplast is a plastid which contains the green coloured pigment called chlorophyll and are present in the green parts of the plants that take part in the process called photosynthesis.
  • The outer chloroplast envelope is made up of lipid (20%-30%).
  • So, the correct answer is '20-30%'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

The packet of thylakoids in a chloroplast is called

  1. Fret channels

  2. Granum

  3. Stroma thylakoid

  4. Photosynthetic thylakoid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • A stack of thylakoid discs is organized to form grana.
  • A thylakoid refers to the membrane-bound internal compartment within the chloroplasts of a plant cell and cyanobacteria.
  • It is a site for light-dependent reactions of photosynthesis. 
  • There are about  10 to 100 thylakoid discs within a granum and about 40- 60 grana in a plant cell.
  • So, the correct answer is 'Granum'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Electron carriers involved in photophosphorylation are located in

  1. Outer chloroplast membrane

  2. Inner chloroplast membrane

  3. Stroma

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

The photophosphorylation reaction involves the conversion of ADP to ATP in the presence of sunlight. This takes place in the thylakoid membrane. The photosystem I and II that involves the electron carriers; are present in the thylakoid membranes of the chloroplast. here the light reaction of photosynthesis takes place.

So, the correct option is 'Thylakoid membrane'

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Photosynthetic pigments found in the chloroplasts occur in

  1. Thylakoid membranes

  2. Plastoglobules

  3. Matrix

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

Photosynthetic or chloroplasts pigments that are found in the thylakoid membrane constitute grana of chloroplasts are the organic molecules that absorb light of specific wavelengths in the visible region due to the presence of conjugated double bonds and are chlorophyll a and b, carotenoids and xanthophylls.

So the correct option is 'Thylakoid membranes'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Chloroplasts stroma of higher plants contains

  1. Chlorophyll

  2. Light dependent reaction enzymes

  3. Light independent reaction enzymes

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

A) Chlorophyll is located within the thylakoid membrane. But chlorophyll is present in both lower (algae) and higher plants and some bacteria as well.
B) The light-dependent reactions use light energy to make ATP and NADPH. This is also seen in lower plants.

C) Light-independent enzymes RuBisCO and RuBP are present only in higher plants.
D) Lysosomes are usually present in animal cells. They can be present in lower plants.
So the correct answer is 'Light independent reaction enzymes'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

In chloroplast, the highest number of protons are found in

  1. Antenna complex

  2. Stroma

  3. Lumen of thylakoids

  4. Inter-membrane space
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

During photosynthetic electron transport, protons (H$^+$) accumulate in the thylakoid space. These protons are released into thylakoid space after each split of water molecule during photooxidation and after each electron transport between PQH$ _2$ to cytochrome-f. Increase in the number of protons in the thylakoid space results in an increase in a proton gradient.

Hence, the correct answer is 'Lumen of thylakoids'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Chlorophyll molecules are located in

  1. Thylakoid membrane

  2. Thylakoid lumen

  3. Stroma

  4. Inner chloroplast membrane
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A) The green pigment chlorophyll is located within the thylakoid membrane.

B) The thylakoid lumen does not contain chlorophyll.
C) The stroma does not contain any pigments.
D) The inner chloroplast membrane does not contain any pigments.
So the correct answer is 'Thylakoid membrane'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Thylakoids possess photosynthetic units called

  1. Quantasomes

  2. Glyoxysomes

  3. Polysomes

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

Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts.

So, the correct option is 'Quantasomes'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Photosynthetic Active Radiation (PAR) has the following range of wavelengths

  1. 340-450 nm

  2. 450-950 nm

  3. 500-600 nm

  4. 400-700 nm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Photosynthetic Active Radiation (PAR), designates the special range of solar radiations from 400 to 700 nm that photosynthetic organisms are able to use for the process of photosynthesis.
SO, the correct answer is '400-700 nm'.
Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Lowest pH inside chloroplast in day time must be found in _______________.

  1. Stroma

  2. Lumen

  3. Intermembrane space

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

During photosynthesis in the light, protons are actively pumped from the stroma into the thylakoid lumen by the electron transport chain. This accumulation of protons in the lumen causes the pH there to drop to its lowest levels.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Which one is not character of antennae?

  1. To make photosynthesis more efficient

  2. To make wider range of absorption of incoming light

  3. Provide electron to primary electron acceptor of photosystem

  4. Reaction center is not part of it
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The light harvesting complexes are made up of hundreds of pigment molecules bound to proteins. Each photosystem has all the pigments (except one molecule of chlorophyll a) forming a  light harvesting system also called antennae. These pigments help to make photosynthesis more efficient by absorbing different wavelengths of light. The single chlorophyll a molecules form the reaction center. Therefore, the reaction center is not a part of antennae. 

So, the correct option is 'Provide electron to primary electron acceptor of photosystem'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

In a chlorophyll molecule, the magnesium is situated in the

  1. corners of porphyrin

  2. centre of porphyrin

  3. isocyclic ring

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

A chlorophyll molecule has a hydrophobic "tail" that embeds the molecule into the thylakoid membrane. The "head" of a chlorophyll molecule is a ring called a porphyrin. The porphyrin ring of chlorophyll, which has a magnesium atom at its centre, is the part of a chlorophyll molecule that absorbs light energy.

So, the correct option is 'Centre of porphyrin'.