Introduction and types of respiration Questions in English

(C) In cold storage,the temperature is maintained at a very low level.
At low temperatures,the metabolic activities of microorganisms,such as bacteria and fungi,are significantly slowed down.
This reduction in metabolic rate leads to a decrease in the rate of bacterial multiplication and enzymatic activity.
Consequently,the spoilage of food is delayed,allowing it to be preserved for a longer duration compared to normal room temperature conditions.

(D) Yeast are facultative aerobes,meaning they are primarily anaerobic but can also survive and respire under aerobic conditions. Therefore,they exhibit both aerobic and anaerobic respiration depending on the availability of oxygen.

(C) $Ascaris$,like most other endoparasites,primarily respires anaerobically due to the low oxygen environment in the host's intestine.
However,it is capable of performing aerobic respiration whenever free $O_2$ is available in the host's intestine.
Therefore,it exhibits both types of respiration depending on the availability of oxygen.

(D) When soil is waterlogged,the air spaces between soil particles are filled with water,which displaces the oxygen $(O_2)$.
Roots require $O_2$ for aerobic respiration to generate the energy $(ATP)$ needed for the active absorption of water and minerals.
In the absence of $O_2$,root cells cannot perform respiration,leading to a lack of energy for metabolic activities.
Consequently,the roots are unable to absorb water and nutrients,eventually leading to the death of the plant roots.

(C) The correct answer is $(C)$.
Tracer technique is a highly effective and important method for studying metabolic pathways.
By using radioactive isotopes such as $C^{14}$ or stable isotopes like $N^{15}$ and introducing them into biological systems (e.g.,plants),scientists can track the movement of atoms through various biochemical reactions.
This technique allows for the precise mapping of pathways in physiological processes such as photosynthesis and respiration.

(C) The Pasteur effect describes the observation that the rate of glycolysis is significantly higher under anaerobic conditions compared to aerobic conditions.
When an organism is shifted from an anaerobic environment to an aerobic environment,the consumption of glucose decreases because the cell can produce more $ATP$ per molecule of glucose through oxidative phosphorylation (aerobic respiration) compared to fermentation (anaerobic respiration).
Therefore,the Pasteur effect is concerned with the shift from anaerobic to aerobic conditions.

(C) Respiration is a metabolic process that occurs in all living cells of an organism to produce energy in the form of $ATP$.
Unlike photosynthesis,which is restricted to green parts containing chlorophyll,respiration occurs continuously in every living cell of the plant,including roots,stems,and leaves,regardless of whether it is day or night.

(D) The rate of respiration is significantly higher in metabolically active and growing regions of a plant.
Germinating seeds are highly active as they require a large amount of energy for the development of the embryo,cell division,and growth.
Therefore,they exhibit a higher rate of respiration compared to dormant structures like dry seeds or mature tissues like collenchyma and leaves.

(B) Respiration is a catabolic,exothermic,and oxidative process.
It involves the breakdown of complex organic molecules like glucose into simpler substances,releasing energy in the form of $ATP$.
Since it involves the removal of electrons and hydrogen atoms from substrates,it is classified as an oxidation reaction.

(C) Respiration is classified into two types based on the substrate used:
$1$. Floating respiration: When carbohydrates or fats are used as respiratory substrates,it is called floating respiration.
$2$. Protoplasmic respiration: When proteins are used as respiratory substrates,it is called protoplasmic respiration.
Since proteins are components of the protoplasm,their breakdown is termed protoplasmic respiration.

(A) The rate of respiration is directly proportional to the metabolic activity of the tissue.
Young leaves are in a phase of rapid growth and cell division,which requires a high amount of energy in the form of $ATP$.
Therefore,young leaves exhibit the highest metabolic rate and consequently the maximum rate of respiration compared to mature or senescent leaves.

(C) Respiration is a catabolic process that occurs in all living cells to produce energy in the form of $ATP$.
It involves the breakdown of respiratory substrates like glucose in the presence or absence of oxygen.
Chlorophyll is a pigment primarily involved in capturing light energy for photosynthesis.
Since respiration occurs in both photosynthetic and non-photosynthetic tissues (like roots or dark-grown cells),the presence of chlorophyll is not necessary for this process.

(C) The $Entner-Doudoroff$ $(ED)$ pathway is an alternative metabolic pathway for the breakdown of glucose into pyruvate.
It was discovered by $Entner$ and $Doudoroff$.
This pathway is primarily found in certain prokaryotes,including $Pseudomonas$ $saccharophila$ and $Pseudomonas$ $fluorescens$,which lack the complete $Embden-Meyerhof-Parnas$ $(EMP)$ pathway or use the $ED$ pathway as their primary mode of glucose catabolism.

(B) Aerobic respiration is a metabolic process that requires oxygen $(O_2)$ as the final electron acceptor in the electron transport chain to produce energy in the form of $ATP$. Without oxygen,the process cannot proceed to completion,making it the essential requirement for aerobic respiration.

(A) The correct matching is as follows:
$1$. Floating respiration: When carbohydrates or fats are used as respiratory substrates,it is called floating respiration. Thus,$A$ matches with $iii$ (Carbohydrates).
$2$. Cytoplasmic respiration: This refers to the breakdown of stored carbohydrates like starch in the cytoplasm. Thus,$B$ matches with $ii$ (Starch).
$3$. Protoplasmic respiration: When proteins are used as respiratory substrates,it is called protoplasmic respiration. Thus,$C$ matches with $i$ (Proteins).
$4$. Lactic acid fermentation: This is a type of anaerobic respiration where lactose or other sugars are converted into lactic acid. Thus,$D$ matches with $iv$ (Lactose).
Therefore,the correct sequence is $A-iii, B-ii, C-i, D-iv$.

(C) Respiration is a controlled biological process that involves a series of enzymatic reactions occurring within cells to release energy. In contrast,combustion is a rapid,uncontrolled,non-enzymatic chemical process that releases energy as heat and light. Therefore,the involvement of enzymes is the key difference between the two processes.

(C) Aerobic respiration involves the complete oxidation of organic substrates (like glucose) into $CO_2$ and $H_2O$ in the presence of oxygen. Since this process involves the oxidation of biological molecules within living cells to release energy,it is commonly referred to as $Bio-oxidation$.

(C) Phenolphthalein is a pH indicator that turns pink in an alkaline solution.
When plant roots are placed in this solution,they perform cellular respiration.
During respiration,roots release $CO_2$ into the surrounding medium.
This $CO_2$ reacts with water to form carbonic acid $(H_2CO_3)$,which neutralizes the alkali in the solution.
As the alkalinity decreases,the pH drops,causing the phenolphthalein to lose its pink color and become colorless.

(A) Respiration is a catabolic process in which organic compounds, primarily glucose, are oxidized to release energy. The overall chemical equation for aerobic respiration is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}$.
Thus, the end products of aerobic respiration in plants are carbon dioxide $(CO_2)$, water $(H_2O)$, and energy in the form of $ATP$.

(C) Cellular respiration is an enzyme-controlled process of biological oxidation of food materials in living cells. Each step of glycolysis,the Krebs cycle,and the electron transport chain is catalyzed by specific enzymes.

(B) Respiration is an $Exothermic$ process because it involves the breakdown of complex organic molecules like glucose into simpler substances,which releases energy in the form of $ATP$ and heat.
Since energy is liberated during this metabolic process,it is classified as exothermic.

(C) Respiration is a fundamental metabolic process that involves the breakdown of respiratory substrates (like glucose) to release energy in the form of $ATP$.
This process is essential for the survival of all living organisms.
Unlike photosynthesis,which is restricted to green cells and requires light,respiration occurs continuously in all living cells of an organism.
It takes place regardless of the presence or absence of light,meaning it occurs both in light and dark conditions to meet the constant energy demands of the cell.

(B) The correct answer is $B$.
Respiration is the process of oxidation of organic compounds (like glucose) in living cells.
This process releases chemical energy in the form of $ATP$,along with water and $CO_2$ as byproducts.
While photosynthesis stores energy,respiration is the primary process by which plants release stored energy for metabolic activities.

(A) Respiration is a catabolic process in which complex organic molecules are broken down to release energy.
Stored food materials,such as carbohydrates (glucose),fats,or proteins,act as the primary respiratory substrates (fuel) for this process.
Therefore,stored food is the source of respiration.

(D) Respiration is a metabolic process in which living organisms break down glucose in the presence or absence of oxygen to produce energy $(ATP)$.
During aerobic respiration, glucose $(C_6H_{12}O_6)$ reacts with oxygen $(O_2)$ to produce carbon dioxide $(CO_2)$, water $(H_2O)$, and energy.
The chemical equation is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
Therefore, carbon dioxide is released as a byproduct during the process of respiration.

(D) Aerobic respiration involves the complete oxidation of organic substrates like glucose into $CO_2$ and $H_2O$ in the presence of oxygen.
This process yields a significantly higher amount of $ATP$ (energy) compared to anaerobic respiration,which only performs partial breakdown of glucose.
For a large organism,the high energy demand is met efficiently by aerobic respiration,making it more advantageous than the energy-deficient anaerobic pathway.

(C) Respiration is a catabolic process in which complex organic molecules (like glucose) are oxidized to release energy.
This energy is not released as heat alone but is captured and stored in the form of $ATP$ (Adenosine Triphosphate) molecules,which serve as the energy currency of the cell.
Therefore,respiration is defined as the process where energy is released from organic compounds and stored in the form of $ATP$.

(A) Respiration is a controlled,enzymatic,multi-step process that releases energy gradually in the form of $ATP$.
In contrast,combustion is a rapid,non-enzymatic,single-step oxidation process that releases energy all at once as heat and light.
Therefore,the primary difference is that in combustion,the energy stored in glucose is released at once,whereas in respiration,it is released in a controlled,step-wise manner.

(C) Plant physiology is the study of the internal physical and chemical processes of plants.
Respiratory activities in plants involve metabolic pathways like glycolysis,the Krebs cycle,and the electron transport chain,which are fundamental physiological processes.
Therefore,'Respiratory activities in plants' is the correct topic under plant physiology.

(B) Respiration is a metabolic process in which living cells break down glucose $(C_6H_{12}O_6)$ in the presence or absence of oxygen to produce energy in the form of $ATP$.
In aerobic respiration, the overall chemical equation is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy} (ATP)$.
As shown in the equation, $CO_2$ (Carbon dioxide) and $H_2O$ are the primary byproducts formed during the process of respiration.

(A) Salt respiration is also known as anion respiration. According to the theory proposed by $Lundegardh$,the rate of respiration in plant cells is directly proportional to the amount of anions absorbed by the cells,rather than the absorption of cations. Therefore,this process is termed as anion respiration.

(A) The inhibition of aerobic respiration by the presence of atmospheric ${O_2}$ is known as the $Pasteur$ effect.
In this process,a high concentration of oxygen inhibits the activity of key respiratory enzymes,thereby reducing the rate of glycolysis and overall respiration.

(B) The $HMP$ pathway,also known as the Pentose Phosphate Pathway $(PPP)$,is an alternative route for glucose oxidation.
Unlike glycolysis and the $TCA$ cycle,the $HMP$ pathway does not require the initial breakdown of glucose through glycolysis.
It involves the direct oxidation of glucose-$6$-phosphate to produce $NADPH$ and pentose sugars,which are essential for biosynthetic processes.

(B) $HMP$ (Hexose Monophosphate) shunt,also known as the Pentose Phosphate Pathway $(PPP)$,is an alternative metabolic pathway to aerobic glycolysis for the oxidation of glucose.
It occurs in the cytoplasm of the cell and is primarily responsible for generating $NADPH$ and pentose sugars (ribose$-5-$phosphate) required for biosynthetic processes.
Unlike glycolysis,it does not directly produce $ATP$ but provides essential precursors for nucleotide and fatty acid synthesis.
Therefore,it serves as an alternative route for glucose metabolism.

(B) At high altitudes,the temperature is generally lower.
Lower temperatures lead to a reduced rate of respiration in plants.
Since respiration consumes the carbohydrates produced during photosynthesis,a lower rate of respiration means that more carbohydrates are available to be stored in the potato tubers.
This accumulation of stored food results in larger potato sizes.

(B) Germination is an energy-intensive process that requires the breakdown of stored food reserves to provide energy for the growing embryo.
This process,known as cellular respiration,requires $O_2$ as the terminal electron acceptor to efficiently produce $ATP$ through aerobic respiration.
In the absence of $O_2$,seeds would have to rely on anaerobic respiration,which produces significantly less energy and leads to the accumulation of toxic byproducts like ethanol or lactic acid,hindering successful germination.
Therefore,the flask containing $O_2$ provides the necessary conditions for aerobic respiration,allowing the seeds to germinate best.

(D) The correct answer is $D$. Water is essential for accelerating enzyme activity. As seeds mature,they lose water content,which leads to a reduction in metabolic activities. Since respiration is an enzyme-mediated process,the decrease in water content causes the rate of respiration to decrease steadily. This is why dry seeds and fruits exhibit minimal respiration.

(C) The rate of respiration depends upon both the quantity and the quality of the protoplasm in the cell.
Young meristematic tissues,which are relatively rich in protoplasm,typically exhibit higher rates of respiration.
Additionally,the water content and the metabolic state (quality) of the protoplasm are crucial factors in controlling the overall rate of respiration.

(B) The $Q_{10}$ (temperature coefficient) is defined as the ratio of the rate of a reaction at one temperature to the rate of the reaction at a temperature $10^{\circ}C$ lower.
For most biological processes,including respiration,the rate of reaction approximately doubles with a $10^{\circ}C$ rise in temperature.
Therefore,the value of $Q_{10}$ for respiration is generally considered to be $2$.

(C) The most appropriate reason for storing green apples at low temperatures is that it slows down the metabolic activities of the fruit.
Specifically,the rate of respiration is significantly reduced at low temperatures.
Since respiration is a catabolic process that consumes stored sugars (like galactose) to provide energy for ripening and senescence,reducing this rate helps the fruit remain fresh for a longer duration.

(C) Internal respiration, also known as cellular respiration, is the metabolic process by which cells convert nutrients into energy in the form of $ATP$.
This process primarily occurs within the $Mitochondria$, which are often referred to as the 'powerhouse of the cell'.
During this process, glucose is oxidized to release energy, carbon dioxide, and water.

(D) Respiration is a metabolic process in which living organisms produce energy by breaking down glucose in the presence or absence of oxygen.
While the intake of $O_2$ and the release of $CO_2$ are parts of the breathing process (ventilation),the fundamental biological purpose of cellular respiration is the liberation of energy in the form of $ATP$.

(B) Respiration is a catabolic process because it involves the breakdown of complex organic molecules (like glucose) into simpler substances.
During cellular respiration,cells consume oxygen $(O_2)$ to oxidize these organic molecules.
This process releases carbon dioxide $(CO_2)$ as a byproduct.
The energy released during this breakdown is trapped and stored in the form of $ATP$ (Adenosine Triphosphate) molecules,which serve as the energy currency of the cell.

(A) Respiration is a metabolic process where organic molecules, primarily glucose, are broken down to release energy.
This energy is stored in the form of $ATP$ $(Adenosine \text{ } Triphosphate)$ molecules.
$ATP$ is a high-energy compound that acts as the primary energy currency of the cell.
Since the energy is stored within the chemical bonds of these molecules, it is referred to as chemical energy.

(A) Breathing is a physical process of inhaling oxygen and exhaling carbon dioxide.
Cellular respiration is a biochemical process that occurs within the cells.
In cellular respiration,glucose is oxidized to $CO_2$ and water,which results in the release of energy in the form of $ATP$.

(B) Submerged plants are aquatic plants that grow entirely underwater.
Even though they are submerged,they perform aerobic respiration.
They utilize the dissolved oxygen present in the water for this process.
Therefore,aerobic respiration occurs by utilizing dissolved oxygen of water.

(B) When the soil is waterlogged,the air spaces in the soil are filled with water,which prevents the roots from obtaining oxygen. Since roots require oxygen for aerobic respiration to generate energy for nutrient uptake,the lack of oxygen leads to the death of the root cells and eventually the plant.

(C) Respiration is a metabolic process that involves the breakdown of respiratory substrates to release energy.
It can occur in the presence of oxygen (aerobic respiration) or in the absence of oxygen (anaerobic respiration or fermentation).
Therefore,respiration is a general term that encompasses both aerobic and anaerobic pathways,meaning it can occur in the presence or absence of $O_2$.

(C) Respiration is a metabolic process that occurs in all living cells.
However,the rate of respiration varies depending on the metabolic activity of the tissue.
$Sclerenchyma$ cells are dead cells at maturity and lack protoplasm,meaning they have no active metabolic processes.
Therefore,they exhibit the minimum (or negligible) rate of respiration compared to active tissues like leaves,stems,or germinating seeds.

(B) Respiration is a catabolic process in which organic compounds (like glucose) are oxidized to release energy in the form of $ATP$. During the process of aerobic respiration, glucose reacts with oxygen to produce $CO_2$, water, and energy. The chemical equation is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$. Thus, $CO_2$ is released as a byproduct during respiration.