Tag: photosynthesis

Questions Related to photosynthesis

Why does the total amount of $CO _2$ in the atmosphere remains constant even though respiration liberates $CO _2$?

biology photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

  1. $CO _2$ acts as a buffer

  2. $CO _2$ is converted to carbohydrates in photosynthesis

  3. $CO _2$ forms carbonic acid

  4. $CO _2$ undergoes cleavage during photosynthesis.

Show answer
Correct Option: B
Explanation:
Most organisms release or exhale $CO _2$ during respiration. This $CO _2$  present in the environment is utilized by plants in the process of photosynthesis with the final product being a carbohydrate. This is how the amount of $CO _2$  in the atmosphere is kept under check.
So, the correct answer is '$CO _2$  is converted to carbohydrates in photosynthesis'.

Thylakoids are found in 

biology photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments action spectrum and absorption spectrum spectrum of electromagnetic radiation

  1. bacteria

  2. blue green algae

  3. higher plants

  4. all of these

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Correct Option: A

In a plant cell chlorophyll is present in:

botany photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments

  1. Caraplasts

  2. Stroma

  3. Leucoplast

  4. Chloroplast

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Correct Option: D
Explanation:

the green coloured, chief photosynthetic pigment present in the chloroplasts of higher plants is called chlorophyll. It is found in algae, and higher plants.

So, the correct option is 'Chloroplasts'.

Minerals controlling synthesis of chlorophyll molecule ______________.

botany photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments

  1. $Ca$ and $K$

  2. $Fe$ and $Mg$

  3. $Mn$ and $K$

  4. $Ca$ and $Mg$

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Correct Option: A

Ginger-Muller counter is used for ________________.

botany photosynthesis site of photosynthesis chloroplast and pigments of photosynthesis pigments

  1. Estimating chlorophyll concentration

  2. Measuring radioactivity

  3. Identifying phytochrome pigments

  4. Measuring the light absorption by chlorophyll

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Correct Option: A

Who is called as 'father of plant physiology'?

botany photosynthesis historical events in photosynthesis history of photosynthesis introduction to photosynthesis

  1. K. V Thimann

  2. Stephen Hales

  3. M. Calvin

  4. E. Rabinowitch

Show answer
Correct Option: B
Explanation:

Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. 

Stephen Hales is considered the 'father of plant physiology' for the many experiments he conducted in 1727; though Julius von Sachs unified the pieces of plant physiology and put them together as a discipline. 

Oxygen released in photosynthesis is due to 

botany photosynthesis modern concept of photosynthesis photosystems photosynthesis in higher plants

  1. Photophosphorylation.

  2. Photolysis of water.

  3. Photorespiration.

  4. Photons.

Show answer
Correct Option: B
Explanation:
Photosynthesis is a process which occurs in two stages. The first is the light dependent reaction where the captured energy of light is used to make the ATP and NADPH. The second stage is where the reactions independent of light use these products to capture and reduce carbon dioxide. Photolysis is part of the light dependent reaction of the photosynthesis process.  
Photosynthesis photolysis can be represented as H$ _2$A + 2 photons --> 2 e$^-$ + 2H$^+$ + A, where the chemical nature of the 'A' depends on the organism. The experiments conducted by Samuel Ruben and Martin Kamen by using radioactive isotopes helped to prove that the oxygen liberated during photosynthesis came from photolysis the water.
Thus, the correct answer is option B.

During photosynthesis, oxygen is evolved from

botany photosynthesis modern concept of photosynthesis photosystems photosynthesis in higher plants

  1. $H _{2}S$.

  2. $H _{2}O$.

  3. $CO _{2}$.

  4. $HCO _{3}$.

Show answer
Correct Option: B
Explanation:

Photosynthesis is a redox reaction in which carbon dioxide is reduced to sugars and water is oxidised to release oxygen.

Photolysis refers to light dependent split of water molecule, which occurs during photosynthesis. The process of photolysis provides electrons for non cyclic electron flow during non cyclic photophosphorylation. Mineral ions required for the process of photolysis are manganese, calcium and chlorine.

In the process of photosynthesis, the water molecule is broken down in

botany photosynthesis modern concept of photosynthesis photosystems photosynthesis in higher plants

  1. Red drop.

  2. Photolysis.

  3. Phoshorylation.

  4. Carbon assimilation.

Show answer
Correct Option: B
Explanation:

Photosynthesis is chemically a redox reaction in which carbon dioxide is reduced and water is oxidised. During light reaction phase of photosynthesis, the electron that has been donated to the electron transport chain is replaced through photolysis (light dependent splitting) of water, a process that not only yields electrons but also is the source of almost all the oxygen in Earths atmosphere. 

Photolysis of water releases ........... gas.

botany photosynthesis modern concept of photosynthesis photosystems photosynthesis in higher plants

  1. ${ CO } _{ 2 }$

  2. ${ O } _{ 2 }$

  3. ${ NH } _{ 3 }$

  4. ${ CH } _{ 3 }$

Show answer
Correct Option: B
Explanation:

Photolysis, the chemical process by which molecules are broken down into smaller units through the absorption of light.

Photolysis of water is the process by which water is split into H+, oxygen, and electrons in the presence of light.
So the answer is 'O2'.