NIOS Class 12 Biology Chapter 12 Solution – Respiration in Plants
NIOS Class 12 Biology Solution Chapter 12 Respiration in Plants . NIOS Class 12 Biology Chapter 12 Question Answers Download PDF. NIOS Class 12 Biology Notes.
Board |
NIOS |
Class |
12th (Higher Secondary) |
Subject |
Biology |
Topic |
Question Answer, Solution, Notes |
INTEXT 12.1
1.) How do plant and other organisms obtain energy for various activites such as growth?
Ans: The green Plants convert solar energy to chemical energy and store it in the form of complex organic molecules. During respiration, they are oxidised and large amount of energy is released. This is stored as ATP. Plants use this ATP for metabolic activities
2.) Name the energy-rich molecule formed during respiration from food.
Ans: ATP is energy-rich molecule formed during respiration from food
3). Give two differences between aerobic and anaerobic respiration.
Ans: Respiration is termed aerobic when oxygen is utilized and much larger quantity of energy in the form of ATP is generated, while in anaerobic oxygen is not utilized and ATP is generated is in very small qualtity
INTEXT 12.2
1.) Name the surfaces that help plants in taking up oxygen from the atmosphere.
Ans: Gaseous exchange takes place through the general body surface of the plants which occurs through the stomata and the lenticels
2.) Name the process by which oxygen is taken up by the plants from the atmosphere.
Ans: Diffusion is process by which oxygen is taken up by the plants from the atmosphere
3.) Name the gases given out by plants during daytime and night.
Ans: Oxygen and Carbondioxide are the gases given out by plants during daytime and night
4.) Why do plants not have any special respiratory organs like animals? Give two reasons.
Ans: Plants not have any special respiratory organs like animals because (a) They have a large surface area to allow exchange of gases from and (b) their requirement of oxygen is much less
INTEXT 12.3
1.) Why is pyruvic acid converted into alcohol or lactic acid during fermentation?
Ans: Pyruvic acid converted into alcohol or lactic acid during fermentation because, In the presence of O2, it is completely broken down to simple forms such as CO2 and H2O.
2Pyruvic acid + 6O2 ⎯→ 6CO2 + 6H2O + 30ATP
(8ATP are obtained from glycolysis) In the absence of O2 they carry out alcoholic fermentation.
2Pyruvic acid ⎯→ 2Ethyl alcohol + 2CO2
2.) Why is there less release of energy during anaerobic respiration?
Ans: This is due to the fact that during anaerobic respiration, organic molecules are only partially oxidised, and the majority of the energy is retained in the end products like alcohol or lactic acid.
3.) List the three phases of aerobic respiration of glucose. Where in the cell do these reactions take place?
Ans: Glycolysis-in cytosol ,
Krebs’ Cycle-matrix of mitochondria,
E.T.C.-inner membrane of mitochondria
4.) What is the role of O2 in aerobic respiration?
Ans: O2 serves as the last electron acceptor for H2, which is then reduced to H2O by removing an electron from the glucose molecule.
5.) Name the substrate and products of Krebs’ Cycle.
Ans: Substrate- Acetyl CoA
Product-2 CO2, 3 NADH2, 1 FADH2, 1 ATP
6.) How do fatty acids enter Krebs’ Cycle?
Ans: Fatty Acid undergoes β oxidation and produces acetyl CoA. This can enter the Kreb’s Cycle.
7.) When the amount of CO2 uptake during photosysthesis is equal to the amount of CO2 generated through respiration, it is called …………… Compensation Point
8.) What is amphibolic pathway?
Ans: Amphinolic pathway is a biochemical pathway that includes both anabolic and catabolic pathway.
INTEXT 12.4
1.) What is the R.Q. for carbohydrates and fats?
Ans: The R.Q. for carbohydrates and fats is one
2.) What is the effect of high concentration of O2 on respiration?
Ans: As the concentration of oxygen rises, the rate of respiration increases. The rate of respiration increases as O2 concentration rises from zero. But after a certain point, the rate of increase declines.
3.) What is the ideal temperature for the process of respiration ?
Ans: 30-35°C is the ideal temperature for the process of respiration
4.) Define R.Q.
It is the ratio of the volume of CO2 evolved to the volume of O2 consumed in respiration. It gives us an idea of the kind of substrate used for respiration
5.) What is the limiting factor of respiration in dry seeds?
Ans: Water for hydration of respiratory enzymes is the limiting factor of respiration in dry seeds.
INTEXT 12.5
1.) Name the products that are formed when RUBP combines with O2. Name the enzyme that is responsible for this reaction.
Ans: Products that are forms when RUBP combines with O2 are1 P.G.A. and 1 Phosphoglycolate. And the enxyme is RUBISCO
2.) Give one point of difference between respiration and photorespiration.?
Ans:
Respiration |
Photorespiration |
Occurs in cytoplasm and mitochndria |
It involves 3 organelles chloroplast, mitochondria peroxisome |
Substrate is glucose |
Substrate is RUBP |
Occurs at both day and night |
Takes place under high O2 and low CO2 and high temperature. Therefore occurs only during the day |
3.) State the conditions under which photorespiration occurs?
Ans: Photorespiration occurs in
(a) Light (b) High concentration of O2
(c) Low concentration of CO2
TERMINAL EXERCISE
1.) Define respiration
Ans: Respiration is the gradual oxidation of complex organic molecules and the release of ATP, which is used for many cellular metabolic processes. It entails gas exchange between the body and the surrounding environment.
2.) What is the role of O2 in electron transport chain (ETC)?
Ans: There is step wise oxidation using the oxygen for further process.
3.) How many molecules of ATP are released when a molecule of glucose is oxidised to
(a) CO2 and H2O: 38 molecules
(b) Ethyl alcohol and CO2 : 2 molecules
4.) Write the equation for aerobic respiration.
Ans: C6H12O6 + 6O2 → 6CO2 + 6H2O
5.) Name the end products of electron transport chains.
Ans: Water, ATP and NAD+ are the end product of ETC
6.) Respiration is a continuous process in green plants. Then why is it that they give out O2 and not CO2 during the day?
Ans: Photosynthesis is a process of exchange of gases which is faster in day time, therefore the amountif oxygen is greater in day tim
7.) What is the site for
a) Glycolysis, :Cytoplasm
(b) Krebs Cycle: Mitochondria
(c) ATP generation by oxidative phosphorylation : Mitochondria
8.)What is the fate of pyruvic acid in the (a) presence, and (b) absence of oxygen? Write the equations representing the processes, that take place in (a) & (b).
Ans: In the presence of O2, it is completely broken down to simple forms such as CO2 and H2O.
2Pyruvic acid + 6O2 ⎯→ 6CO2 + 6H2O + 30ATP
In the absence of O2 they carry out alcoholic fermentation.
2Pyruvic acid ⎯→ 2Ethyl alcohol + 2CO2
9.) What is the significance of stepwise oxidation of organic molecules instead of one step reaction?
Ans: stepwise oxidation of organic molecules is important because many step produces the energy rich ATP molecule that are require in many other process.
10.) What is the significance of photorespiration?
Ans: When there is little carbon dioxide in the air and there is high light, plants photorespire. There is no ATP gain on the whole. When light intensity is exceptionally strong, it prevents photo-oxidation of the chlorophyll pigments.
11.) List the substrates that enter and the products produced in
(a) Glycolysis : substrate are 2 ADP, 1 NAD + , products are NADH, Pyruvic acid, 2 ATP
(b) Krebs Cycle : Substrate are 3 NAD+ , 1 FAD , 2 ADP , acetyl co A and product are 3 NADH, 2 ATP, 1 FADH and 2 CO2
12.) How is yeast useful in industry? Give any three examples.
Ans: Yeast promotes fermentation therefore it is used in industries.
Eg: (i) for making bread, cakes, and biscuits in bakeries.
(ii). For making wine and other alcoholic beverages in breweries
(iii)In producing vinegar and in the tanning and curing of leather
13.) How does exchange of respiratory gases take place in plants
Ans: Stomata pores in plants are where gases are exchanged. During the day, plants absorb carbon dioxide gas to complete their photosynthetic process. Plants require a little quantity of the oxygen gas generated during the photosynthesis process for their breathing.
14.) Define RQ. What is its significance?
Ans: RQ value is crucial for determining the type of substrate utilised in respiration. The Respiratory Quotient can be used to assess the type of substrate being oxidised.
15.) Mention the significance of TCA cycle.
Ans: 1. It is the main channel for the controlled release of decreased coenzymes and energy.
2.) It is the typical pathway for the oxidative degradation of amino acids, fatty acids, glucose (carbohydrates), and other compounds. Acetyl CoA is created by the oxidation of fatty acids, and amino acids from proteins enter the Krebs cycle following deamination (the removal of the -NH2 group).
3.) The Krebs cycle produces a number of the intermediate substances required for the synthesis of other biomolecules such as amino acids, nucleotides, chlorophyll, and lipids.
16.) Why does fermentation yield less energy than aerobic respiration?
Ans: There is incomplete breakdown of glucose in the process of fermentation while in aerobic respiration the breakdown is complete.
17) List any 2 important contributions of PPP in a cell.
Ans: It do not require ETC and a mitochondria
18.) What are the three major phases of glycolysis?
Ans: Glycolysis may be subdivided into 3 major phases:
1.) Conversion of glucose to fructose 1,6 diphosphate via phosphorylation. Two ATPs are used to activate the glucose in this process.
2.) This molecule splits into two sugar phosphates with three carbons each, which are interconvertible
3.) Dehydrogenative oxidation. Each 3-C sugar phosphate undergoes oxidation through hydrogen removal, resulting in decreased NAD, or NADH, and the creation of 2ATPs.
19.) What is the importance of Krebs’ Cycle?
Ans: 1. It is the main channel for the controlled release of decreased coenzymes and energy.
2.) It is the typical pathway for the oxidative degradation of amino acids, fatty acids, glucose (carbohydrates), and other compounds. Acetyl CoA is created by the oxidation of fatty acids, and amino acids from proteins enter the Krebs cycle following deamination (the removal of the -NH2 group).
3.) A succession of intermediary substances, such as amino acids, nucleotides, chlorophyll, and lipids, are produced through the Krebs cycle.
20). Differentiate between aerobic and anaerobic respiration
Ans:
Aerobic |
Anaerobic |
takes place in an oxygen-rich environment.
|
Takes place in the complete absence of oxygen. |
It is more prevalent in higher creatures.
|
occurs in larger animals as well as smaller species like bacteria and fungi when oxygen is scarce. |
leads to the organic substrate being completely oxidised | There is incomplete oxidation of organic substrate.
|
21.) Why is photorespiration a wasteful reaction?
Ans : The response is wasteful. Its primary use is to stop green C3 plant photosynthetic pigments from being damaged by photo-oxidation.
22.) What is respiratory chain or ETC? What is its significance?
Ans: Electron transportation chain is a process by which there is generation of energy rich ATP molecules, this process helps in cellular respiration and photosynthesis.
23.) Discuss the site of Pentose Phosphate Pathway in a cell.
Ans: The site of Pentose Phosphate Pathway is in cystole .
Also See: Next Chapter No. 13 Question Answer