Photosynthesis In Higher Plants Class 11 Important Questions And Answers

Photosynthesis In Higher Plants Class 11:- Every animal, including human beings, depends on plants for their food and oxygen.The green plants synthesis their own food in presence of sunlight,water and minerals this process is known as photosynthesis.By this process plants use light energy to drive the synthesis of the organic compounds.The green plants are also responsible for the release of oxygen in the atmosphere.There are so many experiments which proofs plants require sunlight for photosynthesis,plants release oxygen and takes CO2.

 Photosynthesis In Higher Plants Class 11 – Very Short Answer Type Questions

Q.1. Observe the following given diagram:

a)In which cell either in plant cell or animal  this composition is present ?

b) Can this composition is  inherited by the offspring? If yes then,How?

c) Give the metabolic processes which occurrs at the places marked as (1) and (2) in the given figure

A.1. a) This  is a diagram of chloroplast, which is green in colour and present in plant cells. 

b) Due to  the presence of extranuclear DNA, chloroplast has the potential to self-replicate.

 c) At site 1 – The dark reactions of the photosynthesis takes place in  the stroma of the chloroplasts. At site  2 – This  is the structure of extracellular DNA which is responsible for replication of chloroplasts when this is  necessary in the photosynthesizing cells.

Q.2. Answer the given questions based on following equation:

2H2O 2H+ + O2 + 4e–

a) In which part of the plants does this reaction occur?

b) Write the important role  of this reaction?

A.2.

a) In reaction centre, PS II which is situated in the inner surface of the thylakoid membrane. At this centre electrons are extracted from water and this is called as water splitting centre, and this is catalyzed by the Mn+ and Cl– ions.

b) This reaction releases molecular oxygen as its by-product of the photosynthesis and this molecular oxygen is an important source of oxygen in the air, for living organisms on the earth. These ions of hydrogen are hence produced and they  are used in reducing NADP to NADPH which is a very strong reducing agent.For the synthesis of ATP when electrons released are transferred from PS II to PS I through electron carriers it will create a gradient.

Q.3. In the absence of chloroplasts how do photosynthetic bacteria such as Cyanobacteria conduct photosynthesis? 

A.3. It is prokaryote which contain the photosynthetic pigments in a membrane which are primitive in nature, which can trap and use the solar energy, therefore they can carry out photosynthesis.

Q.4. a)The enzyme NADP reductase is located in which region?

b)The breakdown of the proton gradient causes release of……

A.4. a) Enzyme NADP is located on outer side of the thylakoid membrane.

 b) ATP molecules are released by the breakdown of proton gradient.

Photosynthesis In Higher Plants Class 11 Quiz

Q.5. On monocot plants can we perform girdling experiments ?If yes or no give the reason.

A.5. No, we cannot perform a girdling experiment on monocot plants. We cannot reach to  specific band of  phloem tissues as monocot stem having the vascular bundles which is scattered all over the width of the stem.

Q.6. Does the moonlight enhance  photosynthesis?

A.6. No, moonlight does not enhance photosynthesis and it does not carry enough energy to excite chlorophyll molecules – for the reaction centres PS I and PS II. Therefore light-dependent reactions are not initiated.

Q.7.  In which part of the chloroplast is the NADP reductase enzyme located?  Write the  role in the proton gradient development.

A.7. On the outer side of lamella or thylakoid of the chloroplast NADP reductase enzyme is located.The break down of the proton gradient is  to release energy i.e. NADPH.

Q.8. Write the name of the two parts in ATPase enzyme. Give their arrangement in membrane thylakoid.The conformational changes is shown in the  one part of enzyme?

A.8. Headpiece and a stalk are the two parts in ATPase enzyme and are located all across the inner mitochondrial membrane. The conformational changes occur in headpiece i.e F1 of the enzyme.

Q.9. Write the name of the products used to drive the dark reaction that is formed during the light reaction of photosynthesis.

A.9. ATP and NADPH used to derive the dark reaction that is formed during the light reaction of photosynthesis. It is  used to fix CO2 and to form a glucose molecule.

Q.10.What is the basis of  the C3 and C4 pathways of photosynthesis selected?

A.10.The basis of the carbon atoms in the first stable product of carbon dioxide fixation.

Photosynthesis In Higher Plants Class 11 – Short Answer Type Questions

Q.1.Succulents plants are  able to meet their photosynthetic CO2 requirements as they are known to keep their stomata closed during the day to check the  transpiration how?

A.1.The succulent plants have to close their stomata as they grow in dry and xeric conditions, to prevent water loss during transpiration,gaseous exchange does not take place during the day time. Therefore the plants are  adapted to fix CO2 in the form of malic acid during night time. Malic acid stores CO2 ,it is a four carbon compound. CO2 is liberated during the day time  within the photosynthetic cells.

Q.2. What are accessory pigments? Write their significance in photosynthesis.

A.2. The accessory pigments are chlorophyll-b, xanthophyll, and carotenoids and  they are also referred to as photosynthetic pigments. They work as in accumulating the solar radiations and passing them into chlorophyll-a. The accessory pigment are not directly involved in emission of excited electrons.This pigment absorbs maximum radiations at the regions of – blue and green. Therefore chlorophyll-a is main pigment and other than this pigments are accessory pigments (chlorophyll-A, xanthophyll & carotenoid).

Q.3. Explain that photosynthetic reactions such as dark reactions require light.

A.3. The dark reactions are the light-independent reactions.By the various processes, carbon dioxide is used to reduced  glucose level which does not require light. 

Q.4. Explain the relationship between photosynthesis and respiration.

A.4. Both are related to each other . In both the  mechanisms, plants gain energy in photosynthesis from solar radiations while in the respiration.To get energy in  form of ATP molecules breakdown of glucose molecule takes place. Both the  processes are depends on each other. The respiration uses  end product of the photosynthesis that is glucose in the form of food,to produce ATP for energy. In this process, carbon dioxide and water are released in which photosynthesis uses to produce more sugars.

Q.5.To carry out photosynthesis can green plants kept in dark with proper ventilation? And to maintain survival or growth can they be administered with supplements?

A.5. No, plants kept in dark with proper ventilation can’t carry out photosynthesis as light is very essential for green plants to make their own food. For the  survival, of plants need to be watered properly.

Q.6. Below thick canopies and receiving filtered light how are short plants growing which is able to carry out photosynthesis in the tropical rainforests?

A.6. In the presence of sunlight, plants can  carry out photosynthesis.Rate of photosynthesis is only the factor that gets affected by the quality and intensity of light. Therefore only the rate could vary among the plants growing in different canopy regions.

Q.7. Why does rate of photosynthesis decrease at the higher temperatures?

A.7. Photosynthesis is an enzyme specific process. At an optimum temperature all the enzymes act smoothly. And If the temperature increases further on than 35 °C, the enzymes denature, which affects the rate of photosynthesis.

Photosynthesis In Higher Plants Class 11 – Books

Q.8. a light dependent cyclic process is occurs in a C3 plant, which requires oxygen. Instead of producing the enzymes,it consumes energy.

a) Write the name of  the process

b) Is it necessary for the survival?

c) What are the end products of this process?

d) In which part  does it take place?

A.8.

a) The name of the process is Photorespiration.

b) It is not necessary for the survival of a C3 plant.

c) The end product of this process is  – H2O2

d) This process is takes place in three cell organelles they are – chloroplast, peroxisome, mitochondria

Q.9. The process is occurring throughout the day in which cells are participating in a certain ‘X’ organism, Water, ATP and carbon dioxide are evolved during this  process and it is not a light-dependent process.

a) Which process is described  in above paragraph?

b) Is this process a catabolic process or anabolic process?

c) What are the material of this process?

A.9.

a) In the above paragraph Cellular respiration is described.

b) This is a catabolic process.

c) The Raw material for this process is  – oxygen and glucose molecules, which are the products of photosynthesis.

Q.10. Write the name of the pigment which causes the red colour in tomato and chillies. Is this pigment a photosynthetic pigment?

A.10. Pigment lycopene causes the red colour in the tomato and chillies. Due to the presence of chromoplasts in plants, it gives rise to different colours in the fruits. This  is a kind of plastid which develops different coloured pigments which are not photosynthetic.

Q.11. Why does the colour of a leaf in the dark change? Explain it.The more stable pigment is …..

A.11. The  leaves colour which is stored in  a dark changes from green to pale green or yellow in colour. This is mainly due to the absence of sunlight and chlorophyll pigment. In  dark or during  absence of light, to the photosynthesis does not take place, hence  there is no synthesis of starch and chlorophyll pigment. Chlorophyll a is the most stable pigment.

Q.11.Make a list of the  differences in anatomy of leaf in C3 and C4 plants?

A.11.

C3 plants.	C4 plants.
In the C3 plants, chloroplast is only present  in mesophyll cells.	In the C4 plants, chloroplasts is present in  both cells that are mesophyll and bundle sheath cells.
In C3 plants only one type of chloroplasts is present.	In C4 plants di-morphic types of chloroplasts is present.
In C3 plants the intercellular spaces are larger.	In C4 plants the intercellular spaces are smaller.
In the leaves of C3 plants the Kranz anatomy is absent .	In the leaves of C4 plants the Kranz anatomy is present

Photosynthesis In Higher Plants Class 11 – Long Answer Type Questions

Q.1. Does only in the leaves photosynthesis? If not, then justify what are the other parts that are capable for carrying out photosynthesis? 

A.1. This process of photosynthesis is primarily occurs in the leaves of all green plants. These leaves are designed in such a way that they captures the  sunlight and convert the solar energy into a chemical energy effectively.In some plants, to he  modified parts other than the leaves carry out photosynthesis. In some plants, the roots develop chlorophyll and initiate the photosynthesis, and they are referred to as assimilatory roots.For  Example – Tinospora & Trapa. In the stem of  some plants such as the Opuntia gets modified and adapts to perform functions of leaves, by turning thick, succulent and flattened, by performing photosynthesis, these structures are known as phylloclades. In the Australian Acacia,  petioles take the shape and do the same  function of photosynthesis when the stamina of the leaf fails.

Q.2. Write the location in the cell where these following reactions take place during the process of photosynthesis.

a) Synthesis of NADPH and ATP takes place in

b) Photolysis of water takes  place in

c) CO2 fixation take place in

d) Synthesis of sugar molecule takes place in

e) Synthesis of starch takes place in

A.2.

a)In the Outer side of the thylakoid membrane synthesis of NADPH & ATP takes place.

b) The inner side of the thylakoid membrane photolysis of water takes place.

c)In the Stroma of chloroplast CO2 fixation takes place.

d) In the Chloroplast synthesis of sugar takes place.

e)In the  Cytoplasm synthesis of starch takes place.

Q.3.Write the name of  the pigment which is responsible for its ability to initiate the process of photosynthesis. In the red and blue regions of the spectrum of light,rate of photosynthesis is higher why?

A.3. The chlorophyll pigments contain thylakoid membranes which have the property of excitability and emits the  electron in the excited stage, though it is replaced and transfers  the electron produced from splitting of water molecules. The chlorophyll pigments absorb maximum energy possessed by the red and blue light, therefore getting excited and initiating photosynthesis. Their wavelength lies between the PAR (Photosynthetic Active Radiation). Therefore the rate is higher in red and blue regions.

Photosynthesis In Higher Plants Class 11 – Study materials

Q.4. Write the important events and the end products of light reaction.

A.4. Following are the events: 

The Emission of a pair of electrons is due to excitation of the chlorophyll molecules, using this energy to form ATP from the ADP + Pi, the process is known as photophosphorylation, the water molecule split.

The end product of this process is ATP and NADPH.Light reaction produces reducing power that is the ATP and NADPH2 molecules that are utilized in the dark reaction. The by-product of splitting water is O2.

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