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All questions of Photosynthesis in Higher Plants for ACT Exam
The splitting of water molecule is take place inside
a)Outer membraneb)Lumenc)Stromad)Inner membrane Correct answer is option 'B'. Can you explain this answer?
|
Sathvika Tadri answered |
Splitting of water molecule (photolysis) takes place in lumen of thylakoids
The splitting of water molecules is associated with- a)PS II
- b)PS I
- c)Cyclic phosphorylation
- d)Non-cyclic phosphorylation
Correct answer is option 'A'. Can you explain this answer?
The splitting of water molecules is associated with
a)
PS II
b)
PS I
c)
Cyclic phosphorylation
d)
Non-cyclic phosphorylation
|
Swara Sarkar answered |
This is achieved by electrons available due to splitting of water. The splitting of water is associated with the PS II; water is split into H+, [O] and electrons.
The colour of light not utilized during photosynthesis is :–- a)Violet
- b)Green
- c)Red
- d)Blue
Correct answer is option 'B'. Can you explain this answer?
The colour of light not utilized during photosynthesis is :–
a)
Violet
b)
Green
c)
Red
d)
Blue
|
Jeeshan Ahmed answered |
The only color in the visible spectrum not used at all by green plants would be green because that is the light that is getting reflected off of the plant.
Which pigment is water soluble?- a)Chlorophyll
- b)Carotene
- c)Anthocyanin
- d)Xanthophyll
Correct answer is option 'C'. Can you explain this answer?
Which pigment is water soluble?
a)
Chlorophyll
b)
Carotene
c)
Anthocyanin
d)
Xanthophyll
|
Ashwini Khanna answered |
Anthocyanins (literally "flower blue") are water-soluble flavonoid pigments that appear red to blue, according to pH. They occur in all tissues of higher plants, providing color in leaves, plant stem, roots, flowers, and fruits, though not always in sufficient quantities to be noticeable.
In the half-leaf experiment of photosynthesis, KOH solution is used because- a)It provides O2 to the leaf.
- b)It provides moisture to the leaf.
- c)It helps in CO2 fixation.
- d)It absorbs CO2.
Correct answer is option 'D'. Can you explain this answer?
In the half-leaf experiment of photosynthesis, KOH solution is used because
a)
It provides O2 to the leaf.
b)
It provides moisture to the leaf.
c)
It helps in CO2 fixation.
d)
It absorbs CO2.
|
Krishna Iyer answered |
KOH (Potassium Hydroxide) absorbs carbon dioxide. The leaf inside the bottle containing KOH solution does not become blue-black when compared with the leaf which is exposed to atmospheric air. This shows that carbon dioxide is necessary for photosynthesis.
Can you explain the answer of this question below:Which range of wavelength (in nm) is called photosynthetically active radiation (PAR)?
- A:
400-700
- B:
760-10,000
- C:
100-390
- D:
390-430
The answer is a.
Which range of wavelength (in nm) is called photosynthetically active radiation (PAR)?
400-700
760-10,000
100-390
390-430
|
|
Krishna Iyer answered |
Photosynthetically active radiation. Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis.
Chlorophyll in chloroplasts is located in- a)Grana
- b)Pyrenoid
- c)Stroma
- d)Both grana and stroma
Correct answer is option 'A'. Can you explain this answer?
Chlorophyll in chloroplasts is located in
a)
Grana
b)
Pyrenoid
c)
Stroma
d)
Both grana and stroma
|
|
Gulzar Ahmad answered |
Grana are the stakes of thylakoids which possess green pigment called chlorophyll...
In higher plants, the shape of the chloroplast is- a)Reticulate
- b)Girdle-shaped
- c)Discoid
- d)Cup-shaped
Correct answer is option 'C'. Can you explain this answer?
In higher plants, the shape of the chloroplast is
a)
Reticulate
b)
Girdle-shaped
c)
Discoid
d)
Cup-shaped
|
EduRev JEE answered |
Chloroplasts are the green plastids which take part in photosynthesis and temporary or permanent storage of starch. These are discoid (disc-shaped) in higher plants with diameter of 4-6 μm and thickness of 2-4.μm.
Select the incorrectly matched pair with regard to the C4 cycle.- a)Primary CO2 fixation product – PGA
- b)C4 plant – Maize
- c)Primary CO2 acceptor – PEP
- d)Site of initial carboxylation – Mesophyll cells
- e)Location of enzyme RuBisCO – Bundle sheath cells
Correct answer is option 'A'. Can you explain this answer?
Select the incorrectly matched pair with regard to the C4 cycle.
a)
Primary CO2 fixation product – PGA
b)
C4 plant – Maize
c)
Primary CO2 acceptor – PEP
d)
Site of initial carboxylation – Mesophyll cells
e)
Location of enzyme RuBisCO – Bundle sheath cells
|
|
Vignesh answered |
The primary CO
2
fixation product in C
4
plants is oxaloacetic acid, which is converted to malic acid or aspartic acid that is transported to the bundle sheath cells where the acid is decarboxylated and the CO
2
thus released enters the Calvin cycle.
The C4 plants show higher rate of photosynthesis in- a)Optimum temperature
- b)High temperature
- c)Absence of temperature
- d)Low temperature
Correct answer is option 'B'. Can you explain this answer?
The C4 plants show higher rate of photosynthesis in
a)
Optimum temperature
b)
High temperature
c)
Absence of temperature
d)
Low temperature
|
Shreya Saini answered |
C4 planets show higher rate of photosynthesis in higher temperatures because there is no energy loss in photorespiration in these plants, i.e.at high temperature they show full efficiency of production.
Which one of the following is wrong in relation to photorespiration?- a)It occurs in daytime only.
- b)It occurs in chloroplast.
- c)It is characteristic of C3 plants.
- d)It is characteristic of C4 plants.
Correct answer is option 'D'. Can you explain this answer?
Which one of the following is wrong in relation to photorespiration?
a)
It occurs in daytime only.
b)
It occurs in chloroplast.
c)
It is characteristic of C3 plants.
d)
It is characteristic of C4 plants.
|
Virat answered |
C4 plant does not show photorespiration.
Photophosphorylation means synthesis of- a)ATP from ADP
- b)NADP
- c)ADP from ATP
- d)PGA
Correct answer is option 'A'. Can you explain this answer?
Photophosphorylation means synthesis of
a)
ATP from ADP
b)
NADP
c)
ADP from ATP
d)
PGA
|
|
Ala Habibi answered |
Photophosphorylation is the process in which light energy is converted into chemical energy through the production of ATP. The process of reduction of NADP into NADP+H+ may be denoted as electron transport system (ETS). It is the process of formation of ATP from ADP and inorganic phosphate (ip) utilizing light energy. The flow of electrons through ETS is linked to photophosphorylation. Electron transport chain is a series of electron carriers over which electrons pass in a downhill journey releasing energy at every step that is used in generating an electrochemical proton gradient which helps in synthesizing ATP. Based on the path of electrons, associated photophosphorylation can be identified as non-cyclic and cyclic phosphorylation.
Who described the first action spectrum for photosynthesis?- a)T. W. Engelmann
- b)Cornelius van Niel
- c)Joseph Priestley
- d)Julius von Sachs
Correct answer is option 'A'. Can you explain this answer?
Who described the first action spectrum for photosynthesis?
a)
T. W. Engelmann
b)
Cornelius van Niel
c)
Joseph Priestley
d)
Julius von Sachs
|
Arun Khanna answered |
Engelmann used a prism to split light into its spectral components, and then illuminated a green alga, Cladophora, placed in a suspension of aerobic bacteria. The bacteria were used to detect the sites of oxygen evolution.
He observed that bacteria mainly accumulated in the region of blue and red light of the split spectrum, thus giving the first action spectrum of photosynthesis.
The photosystem II has reaction centre 680nm absorbs- a)Violet light
- b)Blue light
- c)Red light
- d)Green light
Correct answer is option 'C'. Can you explain this answer?
The photosystem II has reaction centre 680nm absorbs
a)
Violet light
b)
Blue light
c)
Red light
d)
Green light
|
Dipanjan Chawla answered |
While PS II has a P680 reaction centre that absorbs red light at 680 nm
Internally, the chloroplast is divided into two parts – the membrane system and the fluid portion called stroma. Labour is equally divided between the two parts with each responsible for a particular function of photosynthesis leading to the formation of sugars. Which part(s) is/are involved in the synthesis of ATP and NADPH?
- a)Both membrane system and stroma
- b)Stroma
- c)Neither membrane system nor stroma
- d)Membrane system
Correct answer is option 'D'. Can you explain this answer?
Internally, the chloroplast is divided into two parts – the membrane system and the fluid portion called stroma. Labour is equally divided between the two parts with each responsible for a particular function of photosynthesis leading to the formation of sugars. Which part(s) is/are involved in the synthesis of ATP and NADPH?
a)
Both membrane system and stroma
b)
Stroma
c)
Neither membrane system nor stroma
d)
Membrane system
|
Gaurav Kumar answered |
There is clear division of labour within the chloroplast. the membrane system is responsible for the light reaction ( trapping light energy and synthesis of ATP and NADPH) while dark reaction i.e., enzymatic reactions for the reduction of carbon dioxide into sugar using ATP and NADPH take place in the stroma.
For fixing one molecule of CO2 in Calvin cycle, required- a)3ATP+2NADPH2
- b)3ATP+1NADPH2
- c)2ATP+3NADPH2
- d)3ATP+3NADPH2
Correct answer is option 'A'. Can you explain this answer?
For fixing one molecule of CO2 in Calvin cycle, required
a)
3ATP+2NADPH2
b)
3ATP+1NADPH2
c)
2ATP+3NADPH2
d)
3ATP+3NADPH2
|
Aashna Mukherjee answered |
Fixing of one molecule of carbon dioxide in Calvin cycle require 3 ATP and 2 NADPH2 as the source of energy. One NADPH2 molecule produce 3 molecules of ATP.
During photosynthesis when PGA is changed into phosphoglyceraldehyde which of the following reaction occur :–- a)Oxidation
- b)Reduction
- c)Electrolysis
- d)Hydrolysis
Correct answer is option 'B'. Can you explain this answer?
During photosynthesis when PGA is changed into phosphoglyceraldehyde which of the following reaction occur :–
a)
Oxidation
b)
Reduction
c)
Electrolysis
d)
Hydrolysis
|
Arjun Chauhan answered |
The conversion of PGA (3-phosphoglycerate) into phosphoglyceraldehyde (PGAL or G3P, glyceraldehyde-3-phosphate) is the sixth step of the Calvin cycle of photosynthesis, and it involves the reduction of PGA by NADPH and ATP. The reaction can be written as:
PGA + NADPH + H+ + ATP → PGAL + NADP+ + ADP + Pi
This reaction is catalyzed by the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which uses the reducing power of NADPH to add a phosphate group to PGA and then remove a hydride ion from the molecule, producing PGAL. This reaction is also known as the reduction phase of the Calvin cycle, as it involves the transfer of electrons from NADPH to PGA, reducing it to PGAL, which can then be used to make glucose or other organic molecules.
PGA + NADPH + H+ + ATP → PGAL + NADP+ + ADP + Pi
This reaction is catalyzed by the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which uses the reducing power of NADPH to add a phosphate group to PGA and then remove a hydride ion from the molecule, producing PGAL. This reaction is also known as the reduction phase of the Calvin cycle, as it involves the transfer of electrons from NADPH to PGA, reducing it to PGAL, which can then be used to make glucose or other organic molecules.
Photorespiration does not occur in- a)C4 plants
- b)C3 plants
- c)Algae
- d)Bacteria
Correct answer is option 'A'. Can you explain this answer?
Photorespiration does not occur in
a)
C4 plants
b)
C3 plants
c)
Algae
d)
Bacteria
|
|
Awantika Gupta answered |
Photorespiration is a wastefull process because it doesn't synthesis ATP.
but in new ncert it is mentioned that the requirements of photorespiration is not known yet.
but in new ncert it is mentioned that the requirements of photorespiration is not known yet.
Chlorophyll is present :–- a)In the grana of chloroplasts
- b)On the surface of chloroplasts
- c)Dispersed through out the chloroplasts
- d)In the stroma of chloroplasts
Correct answer is option 'A'. Can you explain this answer?
Chlorophyll is present :–
a)
In the grana of chloroplasts
b)
On the surface of chloroplasts
c)
Dispersed through out the chloroplasts
d)
In the stroma of chloroplasts
|
Nishanth Khanna answered |
**Chlorophyll is present in the grana of chloroplasts.**
Chloroplasts are the organelles found in plant cells that are responsible for photosynthesis. Photosynthesis is the process by which plants convert sunlight into energy-rich molecules such as glucose. Chlorophyll is the pigment responsible for capturing sunlight and initiating the process of photosynthesis.
Here is a detailed explanation of why chlorophyll is present in the grana of chloroplasts:
**1. Chloroplast Structure:**
Chloroplasts have a complex structure that consists of various compartments. The two main compartments are the grana and the stroma. The grana are stacks of disc-shaped structures called thylakoids, whereas the stroma is the fluid-filled matrix surrounding the grana.
**2. Location of Chlorophyll:**
Chlorophyll molecules are embedded in the thylakoid membranes, which are part of the grana. These membranes contain specialized protein complexes called photosystems that facilitate the capture and conversion of light energy during photosynthesis.
**3. Light-Dependent Reactions:**
The grana are primarily involved in the light-dependent reactions of photosynthesis. During these reactions, chlorophyll molecules in the thylakoid membranes absorb light energy and use it to generate ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy-rich molecules that drive the synthesis of glucose in the subsequent dark reactions.
**4. Chlorophyll Absorption Spectrum:**
Chlorophyll molecules are specifically designed to absorb certain wavelengths of light, primarily in the red and blue regions of the electromagnetic spectrum. This is why plants appear green to our eyes, as chlorophyll reflects green light while absorbing other wavelengths for photosynthesis. The chlorophyll molecules in the grana are arranged in a way that maximizes their exposure to sunlight, allowing for efficient light absorption.
**Conclusion:**
In summary, chlorophyll is present in the grana of chloroplasts because it is embedded in the thylakoid membranes. The grana are the sites where chlorophyll captures light energy during the light-dependent reactions of photosynthesis. This arrangement ensures efficient light absorption and enables plants to convert sunlight into chemical energy.
Chloroplasts are the organelles found in plant cells that are responsible for photosynthesis. Photosynthesis is the process by which plants convert sunlight into energy-rich molecules such as glucose. Chlorophyll is the pigment responsible for capturing sunlight and initiating the process of photosynthesis.
Here is a detailed explanation of why chlorophyll is present in the grana of chloroplasts:
**1. Chloroplast Structure:**
Chloroplasts have a complex structure that consists of various compartments. The two main compartments are the grana and the stroma. The grana are stacks of disc-shaped structures called thylakoids, whereas the stroma is the fluid-filled matrix surrounding the grana.
**2. Location of Chlorophyll:**
Chlorophyll molecules are embedded in the thylakoid membranes, which are part of the grana. These membranes contain specialized protein complexes called photosystems that facilitate the capture and conversion of light energy during photosynthesis.
**3. Light-Dependent Reactions:**
The grana are primarily involved in the light-dependent reactions of photosynthesis. During these reactions, chlorophyll molecules in the thylakoid membranes absorb light energy and use it to generate ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy-rich molecules that drive the synthesis of glucose in the subsequent dark reactions.
**4. Chlorophyll Absorption Spectrum:**
Chlorophyll molecules are specifically designed to absorb certain wavelengths of light, primarily in the red and blue regions of the electromagnetic spectrum. This is why plants appear green to our eyes, as chlorophyll reflects green light while absorbing other wavelengths for photosynthesis. The chlorophyll molecules in the grana are arranged in a way that maximizes their exposure to sunlight, allowing for efficient light absorption.
**Conclusion:**
In summary, chlorophyll is present in the grana of chloroplasts because it is embedded in the thylakoid membranes. The grana are the sites where chlorophyll captures light energy during the light-dependent reactions of photosynthesis. This arrangement ensures efficient light absorption and enables plants to convert sunlight into chemical energy.
What will be left if chlorophyll is burnt?- a)Magnesium
- b)Manganese
- c)Iron
- d)Sulphur
Correct answer is option 'A'. Can you explain this answer?
What will be left if chlorophyll is burnt?
a)
Magnesium
b)
Manganese
c)
Iron
d)
Sulphur
|
|
Aruna Devi answered |
If a molecule of chlorophyll is burnt the organic part of the molecule will be lost and only mineral element i.e., magnesium will be left behind.So the answer is (a) magnesium
Solarisation is- a)Effect of solar light
- b)Destruction of chlorophyll
- c)Formation of chlorophyll
- d)Utilisation of sunlight
Correct answer is option 'B'. Can you explain this answer?
Solarisation is
a)
Effect of solar light
b)
Destruction of chlorophyll
c)
Formation of chlorophyll
d)
Utilisation of sunlight
|
|
Muskaan Dasgupta answered |
Solarisation is the process of destruction of chlorophyll due to prolonged exposure to sunlight. This phenomenon is commonly observed in plants that grow in areas with high solar radiation. Here is a detailed explanation of the process:
Explanation:
Chlorophyll is the green pigment present in the leaves of plants. It plays a crucial role in photosynthesis, which is the process by which plants convert sunlight into energy. However, prolonged exposure to sunlight can damage the chlorophyll molecules, leading to their destruction. This process is known as solarisation.
Solarisation occurs due to the following reasons:
1. High intensity of sunlight: Plants that grow in areas with high solar radiation are more prone to solarisation. This is because the intensity of sunlight in these areas is much higher than in other regions.
2. Extended exposure to sunlight: The longer a plant is exposed to sunlight, the greater the damage to its chlorophyll molecules. This is why solarisation is more common during the summer months, when the days are longer and the sun is more intense.
Effects of solarisation:
1. Reduced photosynthesis: Solarisation damages the chlorophyll molecules, which reduces the plant's ability to carry out photosynthesis. This can lead to stunted growth and reduced yield.
2. Loss of colour: As the chlorophyll molecules are destroyed, the leaves of the plant lose their green colour and turn yellow or brown.
3. Increased susceptibility to pests and diseases: Plants that have been solarised are more susceptible to pests and diseases, as their weakened state makes them more vulnerable to attack.
Prevention of solarisation:
1. Shade: Providing shade to the plants can reduce their exposure to sunlight and prevent solarisation. This can be done by using shade cloth or by planting the crops under trees.
2. Watering: Regular watering can help cool down the plants and reduce the damage caused by solarisation.
3. Timely harvesting: Harvesting the crops before they are fully mature can reduce their exposure to sunlight and prevent solarisation.
In conclusion, solarisation is the process of destruction of chlorophyll due to prolonged exposure to sunlight. It can have a negative impact on plant growth and yield, and can be prevented by providing shade, regular watering, and timely harvesting.
Explanation:
Chlorophyll is the green pigment present in the leaves of plants. It plays a crucial role in photosynthesis, which is the process by which plants convert sunlight into energy. However, prolonged exposure to sunlight can damage the chlorophyll molecules, leading to their destruction. This process is known as solarisation.
Solarisation occurs due to the following reasons:
1. High intensity of sunlight: Plants that grow in areas with high solar radiation are more prone to solarisation. This is because the intensity of sunlight in these areas is much higher than in other regions.
2. Extended exposure to sunlight: The longer a plant is exposed to sunlight, the greater the damage to its chlorophyll molecules. This is why solarisation is more common during the summer months, when the days are longer and the sun is more intense.
Effects of solarisation:
1. Reduced photosynthesis: Solarisation damages the chlorophyll molecules, which reduces the plant's ability to carry out photosynthesis. This can lead to stunted growth and reduced yield.
2. Loss of colour: As the chlorophyll molecules are destroyed, the leaves of the plant lose their green colour and turn yellow or brown.
3. Increased susceptibility to pests and diseases: Plants that have been solarised are more susceptible to pests and diseases, as their weakened state makes them more vulnerable to attack.
Prevention of solarisation:
1. Shade: Providing shade to the plants can reduce their exposure to sunlight and prevent solarisation. This can be done by using shade cloth or by planting the crops under trees.
2. Watering: Regular watering can help cool down the plants and reduce the damage caused by solarisation.
3. Timely harvesting: Harvesting the crops before they are fully mature can reduce their exposure to sunlight and prevent solarisation.
In conclusion, solarisation is the process of destruction of chlorophyll due to prolonged exposure to sunlight. It can have a negative impact on plant growth and yield, and can be prevented by providing shade, regular watering, and timely harvesting.
In PSI, the reaction centre the chlorophyll a has an absorption peak at- a)780nm
- b)700nm
- c)680nm
- d)800nm
Correct answer is option 'B'. Can you explain this answer?
In PSI, the reaction centre the chlorophyll a has an absorption peak at
a)
780nm
b)
700nm
c)
680nm
d)
800nm
|
|
Vartika Shukla (NEET Aspirant) answered |
In PS-I, the reaction centre chlorophyll a has an absorption peak at 700 nm, hence, is called P 700 while in PS-H, it has absorption maxima at 680 nm, so is called P 680.
so the correct answer is b) 700nm
so the correct answer is b) 700nm
C-4 plants are found among- a)Only gramineae
- b)Only monocot
- c)Only dicot
- d)Monocots as well as dicots
Correct answer is option 'D'. Can you explain this answer?
C-4 plants are found among
a)
Only gramineae
b)
Only monocot
c)
Only dicot
d)
Monocots as well as dicots
|
Rajat Kapoor answered |
A C4 plant is a plant that cycles carbon dioxide into four-carbon sugar compounds to enter into the Calvin cycle. These plants are very efficient in hot, dry climates and make a lot of energy. Many foods we eat are C4 plants, like corn, pineapple, and sugar cane.
Who demonstrated the importance of sunlight for the process of photosynthesis?- a)Robert Hill
- b)Engelmann
- c)Jan Ingenhousz
- d)Joseph Priestley
Correct answer is option 'C'. Can you explain this answer?
Who demonstrated the importance of sunlight for the process of photosynthesis?
a)
Robert Hill
b)
Engelmann
c)
Jan Ingenhousz
d)
Joseph Priestley
|
Pooja Mehta answered |
Jan Ingenhousz is best known for his discovery of photosynthesis, the process by which green plants absorb carbon dioxide in the presence of sunlight and release oxygen. Through an ingenious series of experiments, Ingenhousz proved that plant leaves need sunlight rather than heat in order to produce oxygen.
"Kranz Anatomy" is found in- a)Flower
- b)Seed
- c)Leaves
- d)Stem
Correct answer is option 'C'. Can you explain this answer?
"Kranz Anatomy" is found in
a)
Flower
b)
Seed
c)
Leaves
d)
Stem
|
|
Gopikas S answered |
Kranz anatomy is a special structure in the leaves of plants, that have a C4 pathway of carbon dioxide fixation. The leaves contain a ring of mesophyll cells, containing a few small chloroplasts concerned with the initial fixing of carbon dioxide, surrounding a sheath of parenchyma cells (the bundle sheath) which has large chloroplasts involved in the Calvin cycle. C4 photosynthesis is found in many plant species, mostly in monocots (such as maize, sugar cane and several grasses) but also in many dicots (such as amaranth and flaveria).
Photosynthesis take place in- a)Roots
- b)Leaves
- c)Stem
- d)Flowers
Correct answer is option 'B'. Can you explain this answer?
Photosynthesis take place in
a)
Roots
b)
Leaves
c)
Stem
d)
Flowers
|
Arnav Iyer answered |
Photosynthesis takes place only in the green parts of the plants, mainly the leaves.
The process of taking in CO2 by plants and releasing O2 is termed as- a)Transpiration
- b)Respiration
- c)Photosynthesis
- d)Endosmosis
Correct answer is option 'C'. Can you explain this answer?
The process of taking in CO2 by plants and releasing O2 is termed as
a)
Transpiration
b)
Respiration
c)
Photosynthesis
d)
Endosmosis
|
Ciel Knowledge answered |
The process of taking in CO2 by plants and releasing O2 is occurs in photosynthesis. Photosynthesis is the process by which green plants prepare their own food from CO2 and water using the energy from the sunlight. Glucose is formed in this process which acts as food for the plants. Reaction of photosynthesis is:
6 CO2 + 6 H2O → C6H12O6 + 6 O2
If the CO2 content of the atmosphere is as high as 300 parts per million -- a)All plants would be killed
- b)The plants would not grow properly
- c)Plants would grow for some time and then die.
- d)The plants would thrive well
Correct answer is option 'D'. Can you explain this answer?
If the CO2 content of the atmosphere is as high as 300 parts per million -
a)
All plants would be killed
b)
The plants would not grow properly
c)
Plants would grow for some time and then die.
d)
The plants would thrive well
|
|
Surendra Bishnoi answered |
Option d is correct bcz 300ppm is normal concentration of CO2 so plant activity remain same means thrive well
The first stable product of photosynthesis in C-3 plants is :–- a)3-phosphoglyceric acid
- b)Dihydroxyacetone phosphate
- c)Fructose-1, 6 - diphosphate
- d)Ribulose-1, 5-di phosphate
Correct answer is option 'A'. Can you explain this answer?
The first stable product of photosynthesis in C-3 plants is :–
a)
3-phosphoglyceric acid
b)
Dihydroxyacetone phosphate
c)
Fructose-1, 6 - diphosphate
d)
Ribulose-1, 5-di phosphate
|
|
Vartika Shukla answered |
The first stable product of CO2 fixation in C3 plants is a three-carbon organic acid. The enzyme ribulose-1,5-bisphosphate carboxylase–oxygenase (RUBISCO) combines CO2 with the phosphosugar ribulose 1,5-bisphosphate to form two molecules of 3-phosphoglyceric acid. In contrast, carbon fixation in C4 plants results in the formation of four-carbon organic acids, aspartate and malate, as the first stable product of carbon fixation
Isotopes employed to study the process of photosynthesis reaction.- a)S35 and P32
- b)C14 and O18
- c)N14 and Co60
- d)N14 and O18
Correct answer is option 'B'. Can you explain this answer?
Isotopes employed to study the process of photosynthesis reaction.
a)
S35 and P32
b)
C14 and O18
c)
N14 and Co60
d)
N14 and O18
|
|
Awantika Gupta answered |
Correct reason is C14 and O18 was radioactive so it helped in study of photosynthesis.
Which pigment absorbs the red and far red light?- a)Cytochrome
- b)Phytochrome
- c)Carotenoids
- d)Chlorophyll
Correct answer is option 'B'. Can you explain this answer?
Which pigment absorbs the red and far red light?
a)
Cytochrome
b)
Phytochrome
c)
Carotenoids
d)
Chlorophyll
|
Srishti Shah answered |
**Phytochrome**
Phytochrome is a pigment that plays a crucial role in plant growth and development. It is a photoreceptor protein that absorbs red and far-red light wavelengths. This pigment helps plants sense and respond to changes in light conditions, such as the length of the day and the quality of light.
**Structure and Absorption Spectrum**
Phytochrome exists in two interconvertible forms: the red-light absorbing form (Pr) and the far-red-light absorbing form (Pfr). When Pr absorbs red light, it is converted into Pfr, and when Pfr absorbs far-red light, it is converted back to Pr.
The absorption spectrum of phytochrome shows two peaks: one in the red region (around 660 nm) and another in the far-red region (around 730 nm). These absorption peaks allow phytochrome to efficiently absorb red and far-red light, making it the primary pigment responsible for these light wavelengths in plants.
**Functions of Phytochrome**
1. Seed Germination: Phytochrome controls the germination of seeds by sensing and responding to the presence of light. When seeds are exposed to red light, the conversion of Pr to Pfr triggers the germination process.
2. Photomorphogenesis: Phytochrome regulates various aspects of plant development, including stem elongation, leaf expansion, and branching. In the presence of red light, Pfr promotes growth and development, while in the presence of far-red light, the conversion of Pfr to Pr inhibits growth.
3. Photoperiodism: Phytochrome also plays a crucial role in regulating flowering and flowering time in plants. The ratio of red to far-red light is used by plants to determine the length of the day, which in turn affects the flowering process.
4. Shade Avoidance: Plants can detect changes in light quality and quantity and adjust their growth patterns accordingly. Phytochrome helps plants respond to shade by promoting elongation of stems and leaves, allowing them to reach for more available light.
In conclusion, phytochrome is the pigment that absorbs red and far-red light in plants. This pigment plays a vital role in various physiological processes, including seed germination, photomorphogenesis, photoperiodism, and shade avoidance. By sensing and responding to changes in light conditions, phytochrome helps plants optimize their growth and development.
Phytochrome is a pigment that plays a crucial role in plant growth and development. It is a photoreceptor protein that absorbs red and far-red light wavelengths. This pigment helps plants sense and respond to changes in light conditions, such as the length of the day and the quality of light.
**Structure and Absorption Spectrum**
Phytochrome exists in two interconvertible forms: the red-light absorbing form (Pr) and the far-red-light absorbing form (Pfr). When Pr absorbs red light, it is converted into Pfr, and when Pfr absorbs far-red light, it is converted back to Pr.
The absorption spectrum of phytochrome shows two peaks: one in the red region (around 660 nm) and another in the far-red region (around 730 nm). These absorption peaks allow phytochrome to efficiently absorb red and far-red light, making it the primary pigment responsible for these light wavelengths in plants.
**Functions of Phytochrome**
1. Seed Germination: Phytochrome controls the germination of seeds by sensing and responding to the presence of light. When seeds are exposed to red light, the conversion of Pr to Pfr triggers the germination process.
2. Photomorphogenesis: Phytochrome regulates various aspects of plant development, including stem elongation, leaf expansion, and branching. In the presence of red light, Pfr promotes growth and development, while in the presence of far-red light, the conversion of Pfr to Pr inhibits growth.
3. Photoperiodism: Phytochrome also plays a crucial role in regulating flowering and flowering time in plants. The ratio of red to far-red light is used by plants to determine the length of the day, which in turn affects the flowering process.
4. Shade Avoidance: Plants can detect changes in light quality and quantity and adjust their growth patterns accordingly. Phytochrome helps plants respond to shade by promoting elongation of stems and leaves, allowing them to reach for more available light.
In conclusion, phytochrome is the pigment that absorbs red and far-red light in plants. This pigment plays a vital role in various physiological processes, including seed germination, photomorphogenesis, photoperiodism, and shade avoidance. By sensing and responding to changes in light conditions, phytochrome helps plants optimize their growth and development.
The path of CO2 in the dark reactions of photosynthesis was sucessfully traced by the use of the following :–- a)O218
- b)C14O2
- c) P32
- d)X - rays
Correct answer is option 'B'. Can you explain this answer?
The path of CO2 in the dark reactions of photosynthesis was sucessfully traced by the use of the following :–
a)
O218
b)
C14O2
c)
P32
d)
X - rays
|
Maheshwar Saini answered |
Enzyme RUBISCO has an affinity for both
CO
2
and
O
2
and its name changes depending on who it is binding to. When it binds to oxygen, it is called ribulose bisphosphate oxygenase. Though the affinity of RUBISCO to oxygen is said to be more than that for
CO
2
, it depends upon the concentration of
O
2
and
CO
2
and temperature conditions which ultimately decide what RUBISCO binds to.
The site in chloroplast which is responsible for trapping for light energy is- a)Grana
- b)Stroma
- c)Ribosomes
- d)Stromal lamellae
Correct answer is option 'A'. Can you explain this answer?
The site in chloroplast which is responsible for trapping for light energy is
a)
Grana
b)
Stroma
c)
Ribosomes
d)
Stromal lamellae
|
Shruti Chauhan answered |
In chloroplast there is the membranous system consisting of grana, the stroma lamellae, and the fluid stroma. There is a clear division of labour within the chloroplast. The granum is responsible for trapping the light energy.
Presence of carotenes in chloroplast helps in- a)ATP synthesis
- b)Transferring radiant energy into chemical energy
- c)Protecting chlorophyll molecules from photooxidation
- d)Absorption of longer wavelength of light
Correct answer is option 'C'. Can you explain this answer?
Presence of carotenes in chloroplast helps in
a)
ATP synthesis
b)
Transferring radiant energy into chemical energy
c)
Protecting chlorophyll molecules from photooxidation
d)
Absorption of longer wavelength of light
|
|
Suraj Vishwakarma answered |
Nascent oxygen highly energetic and carotene lower the energy of oxygen due to that it prevent the chlorophyll from photoxidation
Our present day view regarding photosynthesis is that- a)Converts light energy into chemical energy
- b)Creates useful energy
- c)Fixes CO2 into carbohydrates
- d)Reverses the action of respiration
Correct answer is option 'A'. Can you explain this answer?
Our present day view regarding photosynthesis is that
a)
Converts light energy into chemical energy
b)
Creates useful energy
c)
Fixes CO2 into carbohydrates
d)
Reverses the action of respiration
|
Om Desai answered |
Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of organic molecules (e.g., sugars). During the process of photosynthesis, light penetrates the cell and passes into the chloroplast. The light energy is intercepted by chlorophyll molecules on the granal stacks. Some of the light energy is converted to chemical energy. During this process, a phosphate is added to a molecule to cause the formation of ATP. The third phosphate chemical bond contains the new chemical energy. The ATP then provides energy to some of the other photosynthetic reactions that are causing the conversion of CO2 into sugars.
PGA as the first CO2 fixation product was discovered in photosynthesis of- a)Angiosperm
- b)Bryophytes
- c)Algae
- d)Gymnosperm
Correct answer is option 'C'. Can you explain this answer?
PGA as the first CO2 fixation product was discovered in photosynthesis of
a)
Angiosperm
b)
Bryophytes
c)
Algae
d)
Gymnosperm
|
Abhiram Basu answered |
Photosynthesis and CO2 fixation
Photosynthesis is a process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into organic compounds and oxygen. This process is essential for life on earth as it produces the oxygen that we breathe and provides food for organisms that cannot produce their own.
CO2 fixation is the process by which carbon dioxide is transformed into an organic molecule that can be used by living organisms. This process is important because carbon dioxide is an essential component of the atmosphere, but it is not readily available to most organisms in its gaseous form.
PGA as the first CO2 fixation product
PGA (phosphoglyceric acid) is the first stable product of CO2 fixation in photosynthesis. It is formed when carbon dioxide combines with a five-carbon sugar called ribulose bisphosphate (RuBP) in a reaction catalyzed by the enzyme Rubisco (ribulose bisphosphate carboxylase/oxygenase).
Discovery of PGA
The discovery of PGA as the first CO2 fixation product was made by Melvin Calvin and his colleagues in the 1940s. They used radioactive carbon-14 to trace the movement of carbon through the photosynthetic process and discovered that PGA was the first stable product of CO2 fixation.
Source of PGA
PGA is produced in the stroma of the chloroplasts in plant cells. It is then used to make glucose and other organic compounds through a series of enzyme-catalyzed reactions known as the Calvin cycle.
Role of algae in PGA discovery
Algae played a crucial role in the discovery of PGA as the first CO2 fixation product. Algae are photosynthetic organisms that are capable of fixing carbon dioxide in a similar way to plants. They were used by Calvin and his colleagues as a model system to study photosynthesis and CO2 fixation.
Conclusion
In conclusion, PGA was discovered as the first CO2 fixation product in photosynthesis by Melvin Calvin and his colleagues in the 1940s. This discovery was made using algae as a model system and has since been confirmed in plants and other photosynthetic organisms.
Photosynthesis is a process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into organic compounds and oxygen. This process is essential for life on earth as it produces the oxygen that we breathe and provides food for organisms that cannot produce their own.
CO2 fixation is the process by which carbon dioxide is transformed into an organic molecule that can be used by living organisms. This process is important because carbon dioxide is an essential component of the atmosphere, but it is not readily available to most organisms in its gaseous form.
PGA as the first CO2 fixation product
PGA (phosphoglyceric acid) is the first stable product of CO2 fixation in photosynthesis. It is formed when carbon dioxide combines with a five-carbon sugar called ribulose bisphosphate (RuBP) in a reaction catalyzed by the enzyme Rubisco (ribulose bisphosphate carboxylase/oxygenase).
Discovery of PGA
The discovery of PGA as the first CO2 fixation product was made by Melvin Calvin and his colleagues in the 1940s. They used radioactive carbon-14 to trace the movement of carbon through the photosynthetic process and discovered that PGA was the first stable product of CO2 fixation.
Source of PGA
PGA is produced in the stroma of the chloroplasts in plant cells. It is then used to make glucose and other organic compounds through a series of enzyme-catalyzed reactions known as the Calvin cycle.
Role of algae in PGA discovery
Algae played a crucial role in the discovery of PGA as the first CO2 fixation product. Algae are photosynthetic organisms that are capable of fixing carbon dioxide in a similar way to plants. They were used by Calvin and his colleagues as a model system to study photosynthesis and CO2 fixation.
Conclusion
In conclusion, PGA was discovered as the first CO2 fixation product in photosynthesis by Melvin Calvin and his colleagues in the 1940s. This discovery was made using algae as a model system and has since been confirmed in plants and other photosynthetic organisms.
Bio-Chemical phase in photosynthesis was first discovered by
a)Blackmanb)Calvinc)Arnond)HillCorrect answer is option 'B'. Can you explain this answer?
|
Ritika Khanna answered |
The concept of dark reaction in photosynthesis was initially explained by Blackman. It is thus also known by the name Blackman’s reaction. This is basically the stage wherein the chemical process of photosynthesis takes place without the use of sunlight. The reaction occurs in the stroma of the chloroplast.
Percentage of chlorophyll in a normal chloroplast- a)5 - 10%
- b)40-50%
- c)65 - 75%
- d)90 - 95%
Correct answer is option 'A'. Can you explain this answer?
Percentage of chlorophyll in a normal chloroplast
a)
5 - 10%
b)
40-50%
c)
65 - 75%
d)
90 - 95%
|
|
Afifa Aaliya answered |
Percentage of a chlorophyll in normal chloroplast is 5 to 10.The concentration of a chlorophyll in a chloroplast is approx 30mM.
So option " A " is correct answer.
So option " A " is correct answer.
Carbon dioxide acceptor in C4 plants is :–- a)Phosphoenol pyruvic acid (PEP)
- b)Ribulose-1, 5 - di phosphate
- c)NADP
- d)Ribulose-5 - phosphate
Correct answer is option 'A'. Can you explain this answer?
Carbon dioxide acceptor in C4 plants is :–
a)
Phosphoenol pyruvic acid (PEP)
b)
Ribulose-1, 5 - di phosphate
c)
NADP
d)
Ribulose-5 - phosphate
|
Debolina Desai answered |
Carbon Dioxide Acceptor in C4 Plants: Phosphoenol Pyruvic Acid (PEP)
In C4 plants, carbon dioxide (CO2) is initially fixed into a four-carbon compound called oxaloacetate (OAA) in the mesophyll cells of the leaves. The enzyme responsible for this initial fixation is phosphoenolpyruvate carboxylase (PEP carboxylase).
1. C4 Photosynthesis
C4 plants have evolved an efficient mechanism called C4 photosynthesis to overcome the limitations of the enzyme Rubisco, which has a low affinity for CO2 and can also catalyze reactions with oxygen, leading to photorespiration. C4 plants have specialized leaf anatomy, with two types of cells: mesophyll cells and bundle sheath cells.
2. Mesophyll Cells
In C4 plants, CO2 is first fixed into a three-carbon compound called phosphoenolpyruvate (PEP) by the enzyme PEP carboxylase in the mesophyll cells. This process occurs in the presence of ATP, and the reaction forms a four-carbon compound called oxaloacetate (OAA). This initial fixation of CO2 occurs in the mesophyll cells and is independent of light.
3. PEP Carboxylase
PEP carboxylase is an enzyme found in the mesophyll cells of C4 plants. It has a higher affinity for CO2 than Rubisco and does not catalyze reactions with oxygen. PEP carboxylase is not inhibited by oxygen and has a higher optimal temperature than Rubisco, allowing C4 plants to efficiently fix CO2 even under high temperatures.
4. Role of PEP in C4 Plants
The oxaloacetate (OAA) formed in the mesophyll cells is then converted into malate or aspartate, which can be transported to the bundle sheath cells, where the Calvin cycle takes place. In the bundle sheath cells, malate or aspartate is decarboxylated, releasing CO2, which is then fixed by Rubisco in the Calvin cycle.
5. Advantages of C4 Photosynthesis
C4 plants have several advantages over C3 plants (plants that use the Calvin cycle for photosynthesis):
- Increased efficiency in carbon fixation, especially under high temperature and light conditions
- Reduced photorespiration, leading to higher rates of photosynthesis and growth
- Ability to grow in environments with limited water availability and high temperatures, such as tropical areas
Overall, the carbon dioxide acceptor in C4 plants is phosphoenolpyruvate (PEP), which is fixed into oxaloacetate (OAA) by the enzyme PEP carboxylase in the mesophyll cells. This initial fixation of CO2 allows C4 plants to overcome the limitations of Rubisco and efficiently perform photosynthesis even under challenging environmental conditions.
In C4 plants, carbon dioxide (CO2) is initially fixed into a four-carbon compound called oxaloacetate (OAA) in the mesophyll cells of the leaves. The enzyme responsible for this initial fixation is phosphoenolpyruvate carboxylase (PEP carboxylase).
1. C4 Photosynthesis
C4 plants have evolved an efficient mechanism called C4 photosynthesis to overcome the limitations of the enzyme Rubisco, which has a low affinity for CO2 and can also catalyze reactions with oxygen, leading to photorespiration. C4 plants have specialized leaf anatomy, with two types of cells: mesophyll cells and bundle sheath cells.
2. Mesophyll Cells
In C4 plants, CO2 is first fixed into a three-carbon compound called phosphoenolpyruvate (PEP) by the enzyme PEP carboxylase in the mesophyll cells. This process occurs in the presence of ATP, and the reaction forms a four-carbon compound called oxaloacetate (OAA). This initial fixation of CO2 occurs in the mesophyll cells and is independent of light.
3. PEP Carboxylase
PEP carboxylase is an enzyme found in the mesophyll cells of C4 plants. It has a higher affinity for CO2 than Rubisco and does not catalyze reactions with oxygen. PEP carboxylase is not inhibited by oxygen and has a higher optimal temperature than Rubisco, allowing C4 plants to efficiently fix CO2 even under high temperatures.
4. Role of PEP in C4 Plants
The oxaloacetate (OAA) formed in the mesophyll cells is then converted into malate or aspartate, which can be transported to the bundle sheath cells, where the Calvin cycle takes place. In the bundle sheath cells, malate or aspartate is decarboxylated, releasing CO2, which is then fixed by Rubisco in the Calvin cycle.
5. Advantages of C4 Photosynthesis
C4 plants have several advantages over C3 plants (plants that use the Calvin cycle for photosynthesis):
- Increased efficiency in carbon fixation, especially under high temperature and light conditions
- Reduced photorespiration, leading to higher rates of photosynthesis and growth
- Ability to grow in environments with limited water availability and high temperatures, such as tropical areas
Overall, the carbon dioxide acceptor in C4 plants is phosphoenolpyruvate (PEP), which is fixed into oxaloacetate (OAA) by the enzyme PEP carboxylase in the mesophyll cells. This initial fixation of CO2 allows C4 plants to overcome the limitations of Rubisco and efficiently perform photosynthesis even under challenging environmental conditions.
Number of ATP molecules requried for regeneration phase of RUBP during synthesis of 1 glucose molecule.- a)6
- b)12
- c)18
- d)30
Correct answer is option 'A'. Can you explain this answer?
Number of ATP molecules requried for regeneration phase of RUBP during synthesis of 1 glucose molecule.
a)
6
b)
12
c)
18
d)
30
|
Pooja Choudhary answered |
Ans.
To create 1 surplus G3P requires 3 carbons, and therefore 3 turns of the Calvin cycle. To make one glucose molecule (which can be created from 2 G3P molecules) would require 6 turns of the Calvin cycle.
The stroma of chloroplast contains
- a)Ribosomes
- b)Light independent reaction enzyme
- c)Light dependent reaction enzyme
- d)Chlorophyll
Correct answer is option 'B'. Can you explain this answer?
The stroma of chloroplast contains
a)
Ribosomes
b)
Light independent reaction enzyme
c)
Light dependent reaction enzyme
d)
Chlorophyll
|
|
Jyoti Kapoor answered |
Stroma, in botany, refers to the colorless fluid surrounding the grana within the chloroplast. Within the stroma are grana, stacks of thylakoids, the sub-organelles, the daughter cells, where photosynthesis is commenced before the chemical changes are completed in the stroma. Photosynthesis occurs in two stages.
In angiosperms, synthesis of chlorophyll occurs in presence of :-- a)Phytochrome
- b)Light
- c)Cytochrome
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
In angiosperms, synthesis of chlorophyll occurs in presence of :-
a)
Phytochrome
b)
Light
c)
Cytochrome
d)
None of the above
|
|
Hitakshi Tamta answered |
Chlorophyll are light harvesting cyclic tetrapyrrole compounds. The chlorophyll biosynthesis requires iron and magnesium mineral ions. The succinyl CoA, an intermediate of Krebs cycle and the amino acid glycine initiate the biosynthesis of chlorophyll 'A', leading to production of protochlorophyllide or protochlorophyll. The protochlorophyllide or protochlorophyll is converted to chlorophyll 'A' in presence of light. Thus, In angiosperms chlorophyll synthesis is a reduction process occurring in the presence light.
Which of the following is likely to be the first substance that a green plant makes in photosynthesis :–- a)A simple sugar
- b)Starch
- c)Fats
- d)Proteins
Correct answer is option 'A'. Can you explain this answer?
Which of the following is likely to be the first substance that a green plant makes in photosynthesis :–
a)
A simple sugar
b)
Starch
c)
Fats
d)
Proteins
|
|
Angel answered |
Simple sugars like glucose and fructose are first produced. They are converted to sucrose for transportation and later on into starch for long term storage. So, the correct answer is option 'A'.
Chapter doubts & questions for Photosynthesis in Higher Plants - Science for ACT 2025 is part of ACT exam preparation. The chapters have been prepared according to the ACT exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for ACT 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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