0

Photosynthetic pigments - class-X

Attempted 0/68 Correct 0 Score 0

Which of the following processes forms chemical potential energy from electromagnetic energy?

  1. Respiration

  2. Photosynthesis

  3. Decomposition

  4. Nitrogen fixation

  5. Fermentation


Correct Option: B
Explanation:

Electromagnetic energy is the same as radiation or light energy. This type of kinetic energy can take the form of visible light waves, like the light from a candle or a light bulb, or invisible waves, like radio waves, microwaves, x-rays and gamma rays. Further, irrespective of where radiation is coming from, it can travel in a vacuum. The electromagnetic energy in plants can be converted to stored chemical energy during photosynthesis. 

Which of the following is responsible for the red, orange and yellow colour of leaves?

  1. Carotenoids

  2. ATP

  3. Leaf decay

  4. Chlorophyll

  5. Over abundance of water


Correct Option: A
Explanation:

Option 'A' is correct.

Carotenoids are responsible for the red, orange and yellow color of leaves. Carotenoids are present with chlorophyll, but in summer the leaves are green because of high levels of chlorophyll. Summer masks the color of carotenoids, During autumn, the color of carotenoids becomes more noticeable because of the degradation of chlorophyll. As the autumn progresses, carotenoids also degrade along with chlorophyll but at a much slower rate. Hence the yellow, orange, red colors become visible.   

The factory for synthesis of sugars in autotrophic eukaryotes is

  1. Chloroplast

  2. Mitochondrion

  3. Endoplasmic reticulum

  4. Ribosome


Correct Option: A
Explanation:

Chloroplasts are the cell organelles where photosynthesis occurs. The light reactions occur in thylakoid membranes and dark reactions occur in stroma of chloroplasts. These reactions result in synthesis of sugars (glucose) in chloroplasts.

The light is trapped by photosynthetic pigments presents in the 

  1. Stroma

  2. Grana

  3. Quantosomes

  4. Periplastidial space


Correct Option: B
Explanation:

The chloroplast is the cell organelles present in plant cells that are responsible for initiating the process of photosynthesis. Chloroplasts are double-membrane bound structures. The stroma of chloroplast is the jelly-fluid like structure in which another membrane system is presently called the thylakoids. These thylakoids are stacked upon each other to form the structure called grana. The grana are connected with each other by an extension of thylakoids called stroma lamellae. Thylakoid of grana has the photosynthetic pigments embedded in it that perform the trapping of sunlight and begin the light reaction of the photosynthesis.

A. Stroma is the region where the dark reaction of the photosynthesis occurs.
B. Grana is the region where the light reaction occurs through the trap of light by the photosynthetic pigment.
C. Quantasomes are the photosynthetic units made of pigments and are present in the grana.
D. Periplastidial space is the region between the inner membrane and the outer membrane of the plastids.
Hence, the correct answer is 'Grana'

Chloroplast stroma contains

  1. Chlorophyll

  2. Light dependent reaction enzymes

  3. Light independent reaction enzymes

  4. Ribosomes


Correct Option: C
Explanation:

In photosynthesis, light-independent reactions are known as dark reactions. This process does not depend directly on the presence of light but is dependent on the products of light reaction i.e., ATP and NADPH. The dark reactions occur through Calvin cycle. They take place in the stromal matrix of the chloroplast. Chloroplast stroma contains light independent reaction enzymes which are required for the reaction. Thus, the correct answer is option C.

Where does the primary photochemical reaction occurs in chloroplast ? Where does the light reaction of photosynthesis taken place?

  1. Stroma

  2. Endoplasmic reticulum

  3. Quantasome or thylakoids (Grana)

  4. Inner membrane of chloroplast


Correct Option: C
Explanation:

In the chloroplast, the primary photochemical reactions occur. During photosynthesis, primary reactions like the light-capturing and ATP-generating reactions occur on grana. Grana are stakes of thylakoids. Quantasomes are particles found in grana. During photosynthesis, the light-dependent reactions take place on the thylakoid membranes. The inside of the thylakoid membrane is called the lumen. Light-independent reactions take place in the stroma. 

Thus, the correct answer is 'Quantasome or thylakoids (Grana).'

Which of the following absorb light energy for photosynthesis : -

  1. Chlorophyll

  2. Water molecule

  3. O$ _{2}$

  4. RUBP


Correct Option: A
Explanation:
A pigment is a compound that absorbs a particular wavelength of visible light. Chlorophyll is a green pigment contained in thylakoid membranes of chloroplasts that are used in photosynthesis by plants. The process of photosynthesis occurs when green plants use the energy of light to convert carbon dioxide (CO2) and water (H2O) into carbohydrates. Light energy is absorbed by chlorophyll, a photosynthetic pigment of the plant, while air containing carbon dioxide and oxygen enters the plant through the leaf stomata.

So, the correct answer is 'Chlorophyll'.

In which of the following parts of the plant cell does photosynthesis occur?

  1. The chloroplasts

  2. The mitochondria

  3. The nucleus

  4. The endoplasmic reticulum


Correct Option: A
Explanation:

The green parts of the plants have the chlorophyll pigment containing chloroplasts. The chloroplast is a type of plastid which plays a major role in the photosynthesis process.

From the following, an organelle containing chlorophyll is

  1. Chloroplast

  2. Endoplasmic reticulum

  3. Nucleus

  4. Mitochondria


Correct Option: A
Explanation:
A. Chloroplasts are greenish plastids which possess photosynthetic pigments, chlorophylls and carotenoids and take part in the synthesis of food. Chlorophylls contain specialised light-absorbing green pigments, therefore help in photosynthesis.
B. Endoplasmic reticulum is a network of reticulum of tiny structures scattered in cytoplasm and composed of three structures- cisternae, tubules and vesicles.
C. Nucleus is a large organelle controlling all the activities of the eukaryotic cells and consists of nuclear envelope, nucleoplasm, nucleolus and chromatin.
D. Mitochondria are cylindrical double membrane organelles and composed of outer, inner membrane, crista and matrix.
So, the correct answer is 'Chloroplast'.

Who gave chemical compositions of chlorophyll and carotenoids?

  1. Park and Biggins

  2. Meyer and French

  3. Willstatter and Stahl

  4. Arnon and Benson.


Correct Option: C
Explanation:

Chlorophyll which is an essential factor in photosynthesis was first isolated and namedby Joseph Bienaime Caventou and Peter Joseph Pelletier but the chemical composition of the same was first elucidated by the German chemist Richard Willstatter followed by Hans Fischer.  Carotenoids which are the organic pigments found in the chloroplasts and chromoplasts of plants and other photosynthetic organisms. These  are oil-soluble molecules comprising of 40 branched carbon units bonded together.

Cytochrome is a :

  1. Mg containing pyrrole rings

  2. Fe containing porphyrin ring

  3. Nucleotide

  4. Alloy of inchrome.


Correct Option: B
Explanation:

(B) Fe containing Porphyrin ring 


Cytochromes are heme proteins that undergo oxidation Reduction reaction and differentiated on the Basis of 

their apoprotein structure, heme structures, and optical absorption in the visible spectrum.

As cytochromes are heme proteins which contain Iron compound in the Tetrapyrrole/Porphyrin structure.

Option B is correct.

If 24 G-3-P molecule are formed in $C _3$ plants. Calculate 
a) the number of $CO _2$ used and 
b) the number of $G3P$ used for regeneration $RuBP$ molecule.

  1. a=12, b=20

  2. a=24, b=48

  3. a=12, b=24

  4. a=20, b=12


Correct Option: C
Explanation:
All together for one G3P to leave the cycle (and go towards glucose blend), three CO2 particles must enter the cycle, giving three new molecules of settled carbon. At the point when three CO2 particles enter the cycle, six G3P atoms are made. One leaves the cycle and is utilized to make glucose, while the other five must be reused to recover three atoms of the RuBP acceptor. 
3 CO2 joins with 3 RuBP acceptors, making 6 atoms of (G3P). 
1 G3P particle leaves the cycle and goes towards making glucose. 
5 G3P particles are reused, recovering 3 RuBP acceptor atoms.
So, the correct option is 'a=12, b=24'.

The number of pigment molecules in quantasome are

  1. 250 - 400

  2. 300 - 900

  3. 500 - 600

  4. 50 - 100


Correct Option: A
Explanation:
  • The thylakoid membrane of chloroplasts contain around 250-400 particles known as quantasomes. They are present on the surface of thylakoid discs in chloroplasts.

What percentage of water, proteins, lipids and pigments are present in chloroplasts respectively?

  1. 50, 25, 15 and 10

  2. 90, 5, 2 and 3

  3. 95, 2, 1 and 2

  4. 85, 10, 3 and 2


Correct Option: B
Explanation:

The chloroplasts are composed of the carbohydrates, lipids, proteins, chlorophyll, carotenoids (carotene and xanthophylls), DNA, RNA and certain enzymes and co-enzymes. The chloroplasts also contain some metallic atoms as Fe, Cu, Mn and Zn. By chemical analysis, these consist of lipids and proteins basically. Lipids are mainly phospholipid components of the membranes and lamellae. Proteins also contain enzymes, which are fully present in mature plastids. By the chemical analysis, it is observed that chloroplastids contain 90% of water, 5% of proteins, 2% of lipids and 3% of pigments.

Thylakoids possess photosynthetic units called

  1. Photosystem.

  2. Electron transport system.

  3. Photolysis complex.

  4. Photophosphorylation complex.


Correct Option: A
Explanation:

Thylakoid is a sheet-like membrane-bound structure which is the site of the light-dependent photosynthesis reactions within the chloroplasts and cyanobacteria. Photosystems are then functional and structural units of protein complexes involved in photosynthesis.

The electron transport chain is a series of the proteins and organic molecules which are found in the inner membrane of the mitochondria. Photolysis is the chemical process by which molecules are broken down into smaller units through the absorption of light.

The synthesis of ATP in chloroplasts, promoted by light, is termed as photophosphorylation

So the correct option is A.

Which pigment absorbs the red and far-red light?

  1. Cytochrome

  2. Phytochrome

  3. Carotenoids

  4. Chlorophyll


Correct Option: B
Explanation:

Phytochrome is a light sensitive pigment in plants and some bacteria and fungi. It exists in two interconvertible forms- Pr and Pfr. Pfr absorbs far red light of 730 nm wavelength. When it absorbs far red light, it converts to its original form, Pr. Thus Pfr is the active form of phytochrome which inhibits flowering.

Solarisation is a process in which

  1. Sugars are formed with the help of solar energy

  2. Chlorophyll is formed

  3. Destrution of chlorophyll and ultimate death of protoplasmic compounds occurs

  4. None of the above


Correct Option: C
Explanation:

Chlorophyll pigments trap sunlight during the process of photosynthesis but get destroyed on exposure to light of higher intensity. An exposure to high light intensity for even a small duration can be harmful. The destruction of chlorophyll when exposed to light of high intensity is called as solarization. It occurs due to irreversible chemical changes in the structure of chlorophyll molecule.

If a tree flowers thrice in a year, in the months of October, January and July in northern India the plant is

  1. Photo and thermo-sensitive.

  2. Photo and thermo-insensitive.

  3. Photosensitive but thermo-insensitive.

  4. Thermo-sensitive but photo-insensitive.


Correct Option: B
Explanation:

Plants are able to detect and respond to light, gravity, changes in temperature and chemicals. Plants respond to the changing seasons to initiate their development and flowering. The photoperiodic stimulus is found to be responsible for flowering, light quality, vernalization, autonomous and GA pathways are also responsible for regulating the flowering time in plants. While vernalization and photoperiodic pathways are environmental dependents, the autonomous pathway promotes flowering in all conditions. Hence for a tree that flowers thrice a year, the plant has to be both photo and thermo-insensitive.

Photosynthetic units are referred as

  1. Quantasomes

  2. Oxysomes

  3. Phycobilisomes

  4. $F _{1}$ particles


Correct Option: A
Explanation:

Photosynthetic units are referred as quantasomes. Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place.

Oxysomes are the structures which are present on the surface of the folded inner membrane of the mitochondria. They are also called as f$ _0$-f$ _1$ particles or ATP synthase. They play an important role in the formation of energy for the functioning of the cell.
The protein complexes attached to thylakoid membranes are known as phycobilisomes. They are made up of phycobiliproteins and help in the transfer of light energy to chlorophyll-a molecule of photosystem-II.
Thus, the correct answer is option A. 

Isotopes employed to study the process of photosynthesis reaction are

  1. $S^{68}\, and\,  P^{32}$

  2. $C^{14}\, and\,  O^{18}$

  3. $N^{14}\, and\,  Co^{60}$

  4. $N^{14}\, and\,  O^{18}$


Correct Option: B
Explanation:

Photosynthesis is a redox reaction in which carbon dioxide is reduced to sugars in dark reaction and water is oxidised to release oxygen in light reaction of photosynthesis. $C^{14}$ label was used to trace the path of carbon in the dark reaction in $C _3$ plants by Calvin, Benson and Basham. The $O^{18}$ label was used by Rumen and Kamen to experimentally prove that the source of oxygen released during light reaction of photosynthesis is water.

Phytochrome is found in

  1. Algae.

  2. Virus.

  3. Gymnosperms.

  4. Angiosperms.


Correct Option: D
Explanation:

The main photoreceptor for photoperiodism and many other light initiated plant responses (such as germination and seedling establishment) is phytochrome. It is a family of about five blue-green pigment proteins, each of which is coded for by a different gene in higher plants, like angiosperms. 

Which of the following is not characterized as an organelle?

  1. Nucleus

  2. Golgi apparatus

  3. Lysosome

  4. Chlorophyll

  5. Chloroplast


Correct Option: D
Explanation:

The eukaryotic cell also possesses several membrane-bound organelles. The cell is composed of the nucleus, Golgi complex, lysosome, chloroplast, mitochondria, etc. Chlorophyll is the coloured pigment inside the chloroplast which is involved in the process of photosynthesis.

Thus, the correct answer is option 'Chlorophyll'.

Which of the following is true about photosynthesis?

  1. Light driven

  2. Photo driven

  3. Anabolic

  4. Enzyme moderated

  5. All of the above


Correct Option: E
Explanation:

Option 'E' is true.

Photosynthesis is an anabolic endergonic and reductive process. Photosynthesis is a process of conversion of light energy into chemical energy. Light not only behaves as a wave but also has energy particles called photons which are different for different wavelengths. 
Photosynthesis is important because it is responsible for the release of oxygen by green plants into the atmosphere.  

Which of the following organelle acts as a site for photosynthesis in plants?

  1. Ribosome

  2. Mitochondria

  3. Chloroplast

  4. Endoplasmic reticulum

  5. Golgi apparatus


Correct Option: C
Explanation:

The process of photosynthesis takes place in the chloroplasts, using chlorophyll, the green pigment involved in photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant. Chloroplasts capture light energy from the sun to produce the free energy stored in ATP and NADPH through a process called photosynthesis.

An association is found between the wavelengths of light absorbed by chlorophyll and wavelengths of length that are associated with the greatest amount of oxygen released by plants. Based on the observation, the function of chlorophyll is

  1. It plays a role in cell respiration.

  2. It plays a role in the light reactions of photosynthesis.

  3. It takes part in $H _2O$ release.

  4. It takes part in $CO _2$ fixation.

  5. It generates energy.


Correct Option: B
Explanation:

Chlorophyll absorbs sunlight of particular wavelength that causes spitting of water at water splitting complex of photosystem II and oxygen gas is released. PSI absorbs light below 680nm while PS II is activated by light below 700 nm; so plants exhibit maximum amount of oxygen released when illuminated with simultaneous exposure to red and far red light. Fixation of $CO _2$ occurs during the dark reaction. Thus, the correct answer is B.

Which of the following best explains why thylakoids are arranged into stacks referred to as grana inside of chloroplasts?

  1. When stacked, thylakoids are better able to exchange raw materials with each other necessary for the production of ATP and NADPH production.

  2. When stacked, photons of light that pass through on thylakoid are likely to be captured by another thylakoid before escaping the bottom of a chloroplast.

  3. When stacked, thylakoids are better protected from the harmful free radicals produced when water is split during the light reactions of photosynthesis.

  4. When stacked, each thylakoid is able to increase their total surface area which allows more electron transport chains to be embedded into each thylakoid membrane.


Correct Option: D
Explanation:

Grana are stacks of sac like structures called the thylakoid. But grana that appears to be formed of a stack of independent units of thylakoids, is a continuous lumen surrounded by the inward folding of the membrane that form the thylakoids. Thylakoid membrane have ETS/ETC used for transport of electrons in the form PS I and PS II. The inward folds increase the surface area.

So, the correct answer is 'When stacked, each thylakoid is able to increase their total surface area which allows more electron transport chains to be embedded into each thylakoid membrane'

Total amount of dry weight of photosynthate produced by all type of plants per annum is

  1. 1.7 million tonnes

  2. 17 million tonnes

  3. 17000 million tonnes

  4. 170000 million tonnes


Correct Option: D
Explanation:

Total amount of dry weight of photosynthate produced by all type of plants per annum is 170000 million tonnes. There are several factors, which limit the formation of dry weight such as reduced nitrogen fixation which will result in reduction of dry weight.

Therefore, the correct answer is option (D).

The site of photosynthesis in blue green algae is

  1. Chromatophores

  2. Mitochondria

  3. Chloroplast

  4. Root hair


Correct Option: A
Explanation:

Blue green algae are prokaryotic orgnanisms and lack membrane bound organelles. Mitochondria and cholroplast are double membrane bound organelles of eukaryotes that serve as site of aerobic respiration and photosynthesis respectively. Chromatophores are the pigment containing membranous structures that serve as site for photosynthesis in BGA. Correct answer is A.

The term thylakoid was coined by

  1. Arnon

  2. Park and Biggins

  3. Menke

  4. Willstatter


Correct Option: C
Explanation:
  • Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the cellular organelle called chloroplast, they are also present in cyanobacteria.
  • It is a site for the light-dependent reactions of photosynthesis. 
  • It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
  • The term thylakoid was coined by Menke in the year 1962.
  • So, the correct answer is 'Menke'.

Intact chloroplasts can be isolated with the help of

  1. Alcohol

  2. Acetone

  3. Carbon disulphide

  4. Sugar solution


Correct Option: B
Explanation:

Intact chloroplast from green leaves can be isolated by the acetone isolation method. The membranes of the chloroplast are proteinaceous in nature so it can be easily isolated by acetone. The samples obtained are loaded to the chromatography apparatus, which shows bands on the chromatogram.

So, the correct option is B. 

Thylakoids occur inside

  1. Mitochondria

  2. Chloroplasts

  3. Golgi apparatus

  4. Endoplasmic reticulum


Correct Option: B
Explanation:
  • Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the cellular organelle called chloroplast, they are also present in cyanobacteria.
  • It is a site for the light-dependent reactions of photosynthesis. 
  • It is made up of a thylakoid membrane which surrounds the thylakoid lumen.
  • So, the correct answer is 'Chloroplasts'.

Number of membranes separating intrathylakoid space from cytoplasm is

  1. 4

  2. 3

  3. 2

  4. 1


Correct Option: B
Explanation:

The chloroplasts are double membrane-bound organelle that is found in the cytoplasm. They have membrane-bound thylakoids in which the photosynthesis takes place. The cytoplasm is thus separated from the intrathylakoid space by 3 membranes. i.e the 2 membranes of the chloroplast, and some membrane of thylakoid.

So, the correct option is '3'

Grana are

  1. Protein storing plastids

  2. Coloured plastids

  3. Stacks of thylakoids

  4. Individual thylakoids present in stroma


Correct Option: C
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 'Stacks of thylakoids'.

In Ulothrix, the shape of chloroplast is

  1. Star-shaped

  2. Cup-shaped

  3. Girdle-shaped

  4. Diffused type


Correct Option: C
Explanation:
  • Ulothrix is a genus of filamentous green algae which are found in marine and fresh waters habitats.
  • They have a single girdle-shaped or band-shaped chloroplast near the peripheral region of the cytoplasm (near the cell wall).
  • So, the correct answer is 'Girdle-shaped'.

Structure associated with chloroplast of green algae is

  1. Pyrenoid

  2. Stigma

  3. Both A and B

  4. Endoplasmic reticulum


Correct Option: C
Explanation:
  • The structure associated with chloroplast of green algae is pyrenoid and stigma.
  • Pyrenoid refers to the cellular microcompartments present within the chloroplasts of the cell of green algae and is a major component of the algal carbon concentrating mechanism.
  • Stigma or eyespot is part of a chloroplast which is found in the motile cells of green algae and helps in finding optimal light conditions for photosynthesis.
  • So, the correct answer is 'Both A and B'.

Number of grana present in a chloroplast is

  1. 10-20

  2. 20-30

  3. 30-40

  4. 40-60


Correct Option: D
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.
  • Within a chloroplast of a plant cell, there are about 40- 60 grana and each granum are composed of 10 to 100 thylakoids.
  • So, the correct answer is '40-60'.

Particles of thylakoid membranes involved in ATP synthesis are called

  1. Quantasomes

  2. $CF _0-CF _1$

  3. Photosystems

  4. Pyrenoids


Correct Option: B
Explanation:
  • The particles of thylakoid membrane responsible for ATP synthesis is a CF$ _1$ -CF$ _O$-ATP synthase.
  • It is embedded in the thylakoid membrane where the CF$ _1$-part is attached to the stroma. 
  • Therefore, ATP synthesis occurs on the stromal side of the thylakoid where the ATP molecules are required for carrying out the light-independent reactions of photosynthesis.
  • So, the correct answer is 'CF$ _0$−CF$ _1$'.

Shape of chloroplast in higher plant is

  1. Discoid

  2. Girdle-shaped

  3. Reticulate

  4. Cup-shaped


Correct Option: A
Explanation:
  • The chloroplast is a discoid plastid which contains chlorophyll (green pigment) within the thylakoid membranes of the organelle.
  • This organelle is present in the green parts of plants where photosynthesis takes place.
  • It is the main site of synthesis of glucose by the process called photosynthesis.
  • The chlorophyll pigment captures the sunlight and converts it into chemical energy and thus, helps in the process of photosynthesis.
  • So, the correct answer is 'Discoid'.

Number of thylakoids in a granum is 

  1. 10-100

  2. 5-10

  3. 100-200

  4. 200-500


Correct Option: A
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'.

Quantasomes occur in

  1. Stroma

  2. Grana/chloroplast

  3. Golgi body

  4. Mitochondria


Correct Option: B
Explanation:
  • Quantasomes occur in the Grana/chloroplast.
  • Quantasomes can be defined as small particles found in the thylakoid membrane of the chloroplasts.
  • These particles are embedded in a paracrystalline form on the surface of thylakoid discs in chloroplasts.
  • So, the correct answer is 'Grana/chloroplast'.

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.


Correct Option: D
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.'.

Lipid content of chloroplast is

  1. 20-30%

  2. 5-10%

  3. 4-5%

  4. 1-2%


Correct Option: A
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%'.

The packet of thylakoids in a chloroplast is called

  1. Fret channels

  2. Granum

  3. Stroma thylakoid

  4. Photosynthetic thylakoid


Correct Option: B
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'.

Electron carriers involved in photophosphorylation are located in

  1. Outer chloroplast membrane

  2. Inner chloroplast membrane

  3. Stroma

  4. Thylakoid membranes


Correct Option: D
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'

Stroma is the ground matrix of

  1. Lysosomes

  2. Oxysomes

  3. Ribosomes

  4. Chloroplast.


Correct Option: D
Explanation:

Stroma, refers to the colourless fluid surrounding the grana within the chloroplast. Within the stroma are grana, stacks of thylakoids, the sub-organelles, where photosynthesis is commenced before the chemical changes are completed in the stroma. The internal space enclosed by the chloroplast double membrane but excluding the thylakoid space. This space, filled with a colorless hydrophilic matrix, contains DNA, ribosomes and some temporary products of photosynthesis also known as chloroplastic stroma.

Match the columns and identify the correct option.

I II
(a) Thylakoids (i) Disc shaped sacs in Golgi apparatus
(b) Cristae (ii) Condensed structure of DNA
(c) Cisternae (iii) Flat membranous sacs in stroma
(d) Chromatin (iv) Infoldings in mitochondria
  1. a-iv, b-iii, c-i, d-ii

  2. a-iii, b-iv, c-i, d-ii

  3. a-iii, b-i, c-iv, d-ii

  4. a-iii, b-iv, c-ii, d-i


Correct Option: B
Explanation:
a) Thylakoid (internal photosynthetic membranes) is a membrane-bound compartment present within the stroma (ground matrix) of the cellular organelle called chloroplast.
b) The inner mitochondrial membrane has folds called cristae which helps in increasing the surface area.
c) The folds of the Golgi apparatus are called cisternae which are called the functional units of this organelle.
d) Chromatin is a viscous, gelatinous substance made up of DNA, RNA, basic proteins called histones or acidic proteins called nonhistones.
So, the correct answer is 'a-iii, b-iv, c-i, d-ii'.

Photosynthetic pigments found in the chloroplasts occur in

  1. Thylakoid membranes

  2. Plastoglobules

  3. Matrix

  4. Chloroplast envelope.


Correct Option: A
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'.

Chloroplasts stroma of higher plants contains

  1. Chlorophyll

  2. Light dependent reaction enzymes

  3. Light independent reaction enzymes

  4. Lysosomes


Correct Option: C
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'.

Dimorphic chloroplasts occur in

  1. Pea

  2. Mango

  3. Sugarcane

  4. Cotton


Correct Option: C
Explanation:

Chloroplast of C4 plants is dimorphic chloroplast because it shows two different types of the chloroplast. 

1). The chloroplast with grana

2). Chloroplast without grana and surrounded to the vascular bundle. 

The chloroplast is of 2 different types hence it's called as the dimorphic chloroplast. And it is best seen among sugarcane of the C4 plants.

So, the correct option is 'Sugarcane'.

Cytochrome $b _6$ and cytochrome f occur in

  1. Ribosomes

  2. Mitochondria

  3. Chloroplasts

  4. Lysosomes


Correct Option: C
Explanation:

The cytochrome b6f complex is an enzyme found in the thylakoid membrane in the chloroplast of plants, cyanobacteria, and green algae, that catalyzes the transfer of electrons from plastoquinol to plastocyanin.


So, the correct option is 'Chloroplast'.

Ground substance of chloroplast is

  1. Stoma

  2. Stroma

  3. Granum

  4. Cisterna.


Correct Option: B
Explanation:
Chloroplast is a double membrane structure which is only present in plants . Chloroplast has fluid which is called stroma it is responsible for dark reaction . There are sac like structure present in it which are called thylakoids which which help in light reaction.

So, the correct option is 'Stroma'.

In chloroplast, the highest number of protons are found in

  1. Antenna complex

  2. Stroma

  3. Lumen of thylakoids

  4. Inter-membrane space


Correct Option: C
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'.

Chlorophyll molecules are located in

  1. Thylakoid membrane

  2. Thylakoid lumen

  3. Stroma

  4. Inner chloroplast membrane


Correct Option: A
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'.

Thylakoids possess photosynthetic units called

  1. Quantasomes

  2. Glyoxysomes

  3. Polysomes

  4. Ribosomes


Correct Option: A
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'.

Quantasomes occur on the surface of

  1. Cristae

  2. Plasmalemma

  3. Nuclear envelope

  4. Thylakoids


Correct Option: D
Explanation:

Quantasomes are composed of lipids and proteins that include various photosynthetic pigments and redox carriers. These are the 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 'Thylakoids'.

Abscises acid is synthesized in.

  1. Chloroplasts

  2. Endoplasmic reticulum

  3. Ribosome's

  4. Peroxisomes


Correct Option: A

Copper-containing blue protein found in the chloroplast is the.

  1. Plastocyanin

  2. Plastoquinone

  3. Cytochrome f

  4. Ferredoxin


Correct Option: A

Extrusion or passage of chromatin from one cell into the cytoplasm of the adjoining cell is due to.

  1. Cytomixis

  2. Cytokinesis

  3. Inversions

  4. Translocation


Correct Option: A

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


Correct Option: D
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'.

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

  1. Stroma

  2. Lumen

  3. Intermembrane space

  4. Thylakoid membrane


Correct Option: A

The individual flattened stacks of membranous structures inside the chloroplasts are known as:

  1. Grana

  2. Stroma

  3. Thylakoids

  4. Cristae


Correct Option: C
Explanation:
A thylakoid is a membrane-bound compartment inside chloroplasts. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen. Chloroplast thylakoids frequently form stacks of disks referred to as grana. So the correct option is ' Thylakoid'

How many structures are of sporophytic origin?
Megasporocyte, Endothecium, Generative cell, Nucellus, Embryo sac, Sporogenous cell, Stigma. Integument

  1. Six

  2. Five

  3. Four

  4. Seven


Correct Option: A

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


Correct Option: C
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'.

Read the given statements A & B and choose the correct option.
A. The ribosomes of the chloroplasts are smaller than the cytoplasmic ribosomes.
B. Chloroplasts can synthesise some of their proteins but they receive other proteins from cytoplasm.

  1. Only statement A is correct.

  2. Only statement B is correct.

  3. Both statements are correct.

  4. Both statements are incorrect.


Correct Option: A
Explanation:

A. Chloroplast ribosomes are similar to those found in the prokaryotes that is 70s type. Eukaryotic ribosomes which are found in the cytoplasm are of 80stype.

B. Most chloroplast and mitochondrial proteins, however, are synthesized outside the organelle on cytosolic ribosomes that are not bound to the rough endoplasmic reticulum.
So the correct option is 'Only statement A is correct'.

In a chlorophyll molecule, the magnesium is situated in the

  1. corners of porphyrin

  2. centre of porphyrin

  3. isocyclic ring

  4. phytol chamber


Correct Option: B
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'.

Enzymes required for photophosphorylation are located in ............ of chloroplast.

  1. Peristromium

  2. Plastidome

  3. Stroma

  4. Quantasome


Correct Option: D
Explanation:

A) The peristomium is the first true body segment in an annelid worm's body in the anterior end.

B) Plastid or plastidome refers to the entire unit where photosynthesis takes place.
C) Enzymes that are responsible for photophosphorylation are not present in the stroma.
D) Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in the surface of thylakoid discs in chloroplasts. They are composed of lipids and proteins that include various photosynthetic pigments and redox carriers. For this reason, they are considered to be photosynthetic units. They occur in 2 sizes: the smaller quantasome is thought to represent the site of photosystem I, the larger to represent the site of photosystem II which are involved in photophosphorylation. 
So the correct answer is 'Quantasome'.

Quantasome is a unit related to

  1. Respiration

  2. Ascent of sap

  3. Growth

  4. Photosynthesis


Correct Option: D
Explanation:

A) Quantasomes are not involved in respiration.
B) Xylem is involved in the ascent of sap. Quantasomes do not play a part in the ascent of sap.

C) Quantasomes are involved in photosynthesis. They do not directly contribute to growth.
D) Quantasomes are particles found on the inner thylakoid membrane of chloroplasts in which photosynthesis takes place.
So the correct answer is 'Photosynthesis'.

On what basis, paper chromatography separates plant pigments?

  1. The non - polarity of the solvents and pigments

  2. The polarity of the paper

  3. The polarity of the pigments

  4. All of the above

  5. None of the above


Correct Option: D
Explanation:

Paper chromatography is a technique that is used in the laboratories to separate plant pigments. The concept used is that this helps to separate the mixture into its component molecules. The molecules migrate, or move up the paper, at different rates because of differences in solubility, molecular mass, and hydrogen bonding with the paper.

- Hide questions