R.Q. Questions in English

(D) $Opuntia$ is a succulent plant that performs Crassulacean Acid Metabolism $(CAM)$.
In $CAM$ plants,stomata remain closed during the day to prevent water loss and open at night for $CO_2$ intake.
During the night,$CO_2$ is fixed into organic acids (like malic acid),and during the day,these acids are decarboxylated to release $CO_2$ for the Calvin cycle.
Because the $CO_2$ released internally is reused for photosynthesis,there is no net exchange of gases with the atmosphere during the day.
Consequently,the Respiratory Quotient $(R.Q.)$ for $CAM$ plants like $Opuntia$ is $0$.

(C) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For carbohydrates,$RQ = 1$.
For fats,$RQ < 1$.
For organic acids (like malic acid or oxalic acid),the amount of $CO_2$ released is greater than the amount of $O_2$ consumed,resulting in an $RQ > 1$.
Therefore,the correct option is $C$.

(C) The Respiratory Quotient $(R.Q.)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For fats,the $R.Q.$ is typically around $0.7$.
Since $0.7 < 1$,the $R.Q.$ of fat is less than $1$.
This occurs because fats are more reduced than carbohydrates and require more oxygen for complete oxidation.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For carbohydrates, the chemical equation is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
Here, the volume of $CO_2$ released is $6$ and the volume of $O_2$ consumed is $6$.
Therefore, $RQ = 6/6 = 1.0$.
Since the ratio is $1:1$ (or $1$), the substrate is a carbohydrate.

(B) The respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For tripalmitin $(C_{51}H_{98}O_6)$, the balanced chemical equation for aerobic respiration is:
$2C_{51}H_{98}O_6 + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$
Using the formula $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$:
$RQ = \frac{102}{145} \approx 0.7$
Therefore, the correct value for the respiratory quotient of tripalmitin is $0.7$.

(C) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
The chemical equation for the aerobic respiration of oxalic acid is:
$(COOH)_2 + 1/2 O_2 \rightarrow 2 CO_2 + H_2O$
Here,the volume of $CO_2$ evolved is $2$ and the volume of $O_2$ consumed is $0.5$.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{2}{0.5} = 4.0$.
Therefore,the $RQ$ of oxalic acid is $4.0$.

(D) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
In anaerobic respiration,$CO_2$ is produced,but no $O_2$ is consumed.
Therefore,the formula becomes: $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{\text{Value}}{0} = \infty$.
Thus,the $RQ$ for anaerobic respiration is infinite.

(C) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For oxalic acid,the chemical equation for aerobic respiration is:
$(COOH)_2 + 1/2 O_2 \rightarrow 2CO_2 + H_2O$
Here,the volume of $CO_2$ evolved is $2$ and the volume of $O_2$ consumed is $0.5$.
Therefore,$RQ = \frac{\text{Volume of } CO_2}{\text{Volume of } O_2} = \frac{2}{0.5} = 4.0$.
Thus,the $RQ$ of oxalic acid is $4.0$.

(C) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For the complete oxidation of glucose $(C_6H_{12}O_6)$, the chemical equation is:
$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$
According to the equation, $6$ molecules of $CO_2$ are produced and $6$ molecules of $O_2$ are consumed.
Therefore, $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{6}{6} = 1$.
Thus, the $RQ$ of glucose is $1$.

(D) To balance the chemical equation for the aerobic respiration of a fat molecule (like tripalmitin), we use the law of conservation of mass.
The general equation is $2(C_{51}H_{98}O_6) + 145 O_2 \rightarrow 102 CO_2 + 98 H_2O + \text{energy}$.
$1$. Carbon atoms: $2 \times 51 = 102$ on the reactant side, and $102$ on the product side.
$2$. Hydrogen atoms: $2 \times 98 = 196$ on the reactant side, and $98 \times 2 = 196$ on the product side.
$3$. Oxygen atoms: $(2 \times 6) + (145 \times 2) = 12 + 290 = 302$ on the reactant side, and $(102 \times 2) + 98 = 204 + 98 = 302$ on the product side.
Thus, the correct reactant is $2(C_{51}H_{98}O_6)$ and the water produced is $98 H_2O$.

(D) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration $(RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}})$.
For carbohydrates (e.g., glucose), the equation is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
Here, $RQ = \frac{6}{6} = 1.0$.
In contrast, fats and proteins are more reduced than carbohydrates, meaning they contain less oxygen relative to their carbon content. Consequently, they require more external oxygen for complete oxidation, resulting in an $RQ$ value of less than $1.0$ (typically $0.7$ for fats and $0.9$ for proteins).
Therefore, carbohydrates have a higher $RQ$ because they are already partially oxygenated, requiring less atmospheric oxygen for complete oxidation.

(D) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
When carbohydrates are used as respiratory substrates,the $RQ$ is $1$.
When fats are used as respiratory substrates,the $RQ$ is less than $1$,typically about $0.7$.
When proteins are used as respiratory substrates,the $RQ$ is approximately $0.9$.

(A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For fats like Tripalmitin $(C_{51}H_{98}O_6)$, the chemical equation for aerobic respiration is:
$2(C_{51}H_{98}O_6) + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$
Calculating the $RQ$:
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{102}{145} \approx 0.7$
Therefore, the $RQ$ of Tripalmitin is $0.7$.

(B) The respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
Since the amount of $CO_2$ produced and $O_2$ consumed varies depending on the chemical nature of the respiratory substrate (e.g.,carbohydrates,fats,or proteins),the $RQ$ value is primarily determined by the type of respiratory substrate being oxidized.

(A) The Respiratory Quotient $(R.Q.)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
Formula: $R.Q. = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
From the given chemical equation: $2(C_{51}H_{98}O_6) + 145 O_2 \rightarrow 102 CO_2 + 98 H_2O + \text{energy}$
Volume of $CO_2$ evolved = $102$
Volume of $O_2$ consumed = $145$
$R.Q. = \frac{102}{145} \approx 0.703$
Therefore, the $R.Q.$ is approximately $0.7$, which is characteristic of fats (triolein).

(C) $R.Q.$ stands for Respiratory Quotient.
It is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
The formula is: $R.Q. = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$.
Therefore, the correct option is $C$.

(C) $Respirometer$ is a device used to measure the rate of respiration of a living organism by measuring its rate of exchange of oxygen and/or carbon dioxide.
It is specifically used to calculate the respiratory quotient $(RQ)$,which is the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
$Auxanometer$ is used to measure the growth of plants.
$Potometer$ is used to measure the rate of transpiration.
$Manometer$ is a general instrument used to measure pressure.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For fatty acids, the oxidation process requires more oxygen relative to the amount of carbon dioxide produced.
For example, in the oxidation of tripalmitin (a fatty acid), the reaction is: $2(C_{51}H_{98}O_6) + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$.
Calculating the $RQ$: $RQ = \frac{\text{Volume of } CO_2}{\text{Volume of } O_2} = \frac{102}{145} \approx 0.7$.
Since $0.7 < 1$, the $RQ$ for fatty acids is always less than $1$.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For fatty acids like tripalmitin $(C_{51}H_{98}O_6)$, the chemical equation for aerobic respiration is:
$2(C_{51}H_{98}O_6) + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$
Calculating the $RQ$:
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{102}{145} \approx 0.7$
Therefore, the $RQ$ value for tripalmitin is $0.7$.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
The formula is: $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$.
From the given balanced chemical equation: $2(C_{51}H_{98}O_6) + 145O_2 \to 102CO_2 + 98H_2O + \text{Energy}$.
Here, the volume of $CO_2$ evolved is $102$ and the volume of $O_2$ consumed is $145$.
Therefore, $RQ = \frac{102}{145} \approx 0.703$, which is approximately $0.7$.
This value is characteristic of fatty substances (like tripalmitin).

(N/A) Respiratory quotient $(RQ)$ or respiratory ratio is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
The value of $RQ$ depends on the type of respiratory substrate. For carbohydrates,the value is $1$.
For fats,the $RQ$ value is always less than $1$ because fats require more oxygen for complete oxidation compared to carbohydrates.
For example,in the respiration of tripalmitin (a fatty acid),$102$ molecules of $CO_2$ are evolved while $145$ molecules of $O_2$ are consumed. Thus,the $RQ$ value for tripalmitin is $102 / 145 = 0.7$.

During aerobic respiration,$O_{2}$ is consumed and $CO_{2}$ is released.
The ratio of the volume of $CO_{2}$ evolved to the volume of $O_{2}$ consumed in respiration is called the respiratory quotient $(RQ)$.
$RQ = \frac{\text{Volume of } CO_{2} \text{ evolved}}{\text{Volume of } O_{2} \text{ consumed}}$
The respiratory quotient depends upon the type of respiratory substrate used during respiration.
$RQ$ of Carbohydrates: When carbohydrates are used as substrate and are completely oxidized,the $RQ$ is $1$,because equal amounts of $CO_{2}$ and $O_{2}$ are evolved and consumed.
Equation: $C_{6}H_{12}O_{6} + 6O_{2} \longrightarrow 6CO_{2} + 6H_{2}O + \text{Energy}$
$RQ = \frac{6CO_{2}}{6O_{2}} = 1.0$
$RQ$ of fat: When fats are used in respiration,the $RQ$ is less than $1$. Calculation for a fatty acid,tripalmitin,if used as a substrate is shown:
$2(C_{51}H_{98}O_{6}) + 145O_{2} \longrightarrow 102CO_{2} + 98H_{2}O + \text{Energy}$
$RQ = \frac{102CO_{2}}{145O_{2}} \approx 0.7$
Protein: When proteins are respiratory substrates,the ratio is about $0.9$.
When organic acids are used for respiration,the $RQ$ remains above $1$.
Example: Equation for respiration of oxalic acid:
$2(COOH)_{2} + O_{2} \longrightarrow 4CO_{2} + 2H_{2}O + \text{Energy}$
$RQ = \frac{4CO_{2}}{1O_{2}} = 4.0$

(D) The rate of respiration in plants depends on the type of respiratory substrate being oxidized.
Different substrates like carbohydrates (glucose),fats,and proteins have different chemical structures and energy contents.
When these substrates are oxidized,the amount of $O_2$ consumed and $CO_2$ released varies,which affects the Respiratory Quotient $(RQ)$ and the overall rate of respiration.
Therefore,the rate of respiration changes depending on whether the substrate is glucose,fat,or protein.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For carbohydrates, the chemical equation for aerobic respiration is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
Here, the volume of $CO_2$ evolved is $6$ and the volume of $O_2$ consumed is $6$.
Therefore, $RQ = \frac{6CO_2}{6O_2} = 1.0$.
Thus, the $RQ$ value for carbohydrates is $1.0$.

(N/A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For fats (e.g., tripalmitin), the chemical equation is:
$2(C_{51}H_{98}O_6) + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$
Using the formula: $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
$RQ = \frac{102}{145} \approx 0.7$
Since the value is less than $1$, it indicates that fats are used as respiratory substrates.

(A) The chemical formula $C_{51}H_{98}O_6$ corresponds to Tripalmitin, which is a common fatty acid (fat) used as a respiratory substrate in plants.
In the context of respiratory quotient $(RQ)$ calculations in $NCERT$ biology, the equation $2(C_{51}H_{98}O_6) + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$ is used to demonstrate the $RQ$ of fats, which is approximately $0.7$.

(A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For carbohydrates,the $RQ$ is $1.0$.
For proteins,the $RQ$ is approximately $0.9$.
For fats,such as tripalmitin (a fatty acid),the $RQ$ is $0.7$ because they require more oxygen for complete oxidation compared to carbohydrates.

(D) The respiratory quotient $(RQ)$ is a dimensionless ratio used in calculations of basal metabolic rate when estimated from carbon dioxide production to oxygen consumption.
It is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during the process of respiration.
The formula is: $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_{2}$ evolved to the volume of $O_{2}$ consumed during respiration.
$RQ = \frac{\text{Volume of } CO_{2} \text{ evolved}}{\text{Volume of } O_{2} \text{ consumed}}$
Since the amount of $O_{2}$ consumed and $CO_{2}$ released depends on the chemical nature of the respiratory substrate (e.g.,carbohydrates,fats,or proteins),the $RQ$ value varies accordingly.

(C) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
If $RQ < 1.0$,it indicates that the volume of $O_2$ consumed is greater than the volume of $CO_2$ released.
This typically occurs when respiratory substrates like fats or proteins are oxidized,as they are more reduced than carbohydrates.
For carbohydrates,$RQ = 1.0$. For organic acids,$RQ > 1.0$. For succulents,$RQ = 0$.

(D) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
When fats are used as respiratory substrates,the $RQ$ is always less than $1$ (typically around $0.7$).
Castor seeds are rich in fats (oils),therefore,they exhibit an $RQ$ of less than $1$.
In contrast,carbohydrates like wheat,millets,and beans typically have an $RQ$ of $1$.

(B) $RQ$ (Respiratory Quotient) is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
It depends primarily on the nature of the respiratory substrate being oxidized.
For carbohydrates,the $RQ$ is $1$. For fats and proteins,it is less than $1$,and for organic acids,it is greater than $1$.

(C) $Respirometer$ is a laboratory apparatus used to measure the rate of respiration of a living organism by measuring its rate of exchange of oxygen and/or carbon dioxide.
It is specifically designed to determine the respiratory quotient $(RQ)$,which is the ratio of the volume of carbon dioxide evolved to the volume of oxygen consumed during respiration.

(C) The respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
When respiratory substrates are fats or proteins,the $RQ$ value is typically less than $1$.
Castor seeds are oilseeds,meaning they are rich in fatty substances (lipids).
Since fats are the primary respiratory substrate in germinating castor seeds,the $RQ$ is less than $1$ (approximately $0.7$).

(C) $RQ$ (Respiratory Quotient) is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
If $RQ < 1$,it indicates that the volume of $CO_2$ released is less than the volume of $O_2$ consumed.
Since $0.6 < 1$,the oxidation of the respiratory substrate consumed more oxygen than the amount of $CO_2$ released.

(B) The respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_{2}$ evolved to the volume of $O_{2}$ consumed during respiration.
The formula is: $RQ = \frac{\text{Volume of } CO_{2} \text{ evolved}}{\text{Volume of } O_{2} \text{ consumed}}$.
From the given balanced chemical equation:
$2(C_{51}H_{98}O_{6}) + 145O_{2} \rightarrow 102CO_{2} + 98H_{2}O + \text{Energy}$.
Here, the number of $CO_{2}$ molecules evolved is $102$ and the number of $O_{2}$ molecules consumed is $145$.
Therefore, $RQ = \frac{102}{145} \approx 0.7$.
Since the substrate is a fatty acid (tripalmitin), the $RQ$ is less than $1$.

(D) In anaerobic respiration, $CO_{2}$ is evolved, but oxygen is not consumed.
Respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_{2}$ evolved to the volume of $O_{2}$ consumed.
$RQ = \frac{\text{Volume of } CO_{2} \text{ evolved}}{\text{Volume of } O_{2} \text{ consumed}}$
In anaerobic respiration (e.g., fermentation in yeast), glucose is broken down into ethanol and $CO_{2}$ without the use of oxygen:
$C_{6}H_{12}O_{6} \xrightarrow{\text{Zymase}} 2C_{2}H_{5}OH + 2CO_{2} + \text{Energy}$
Since the volume of $O_{2}$ consumed is $0$, the $RQ$ becomes $\frac{2}{0}$, which is equal to infinity $(\infty)$.

(D) Respiratory quotient $(RQ)$ is defined as the ratio of the volume of carbon dioxide $(CO_2)$ evolved to the volume of oxygen $(O_2)$ consumed during respiration.
In succulent plants like $Opuntia$, the stomata remain closed during the day to prevent water loss. During the night, they take in $CO_2$ and store it as organic acids (like malic acid). During the day, these organic acids are decarboxylated to release $CO_2$, which is then used in photosynthesis.
Because no $CO_2$ is released into the atmosphere during the respiration process in these plants, the volume of $CO_2$ evolved is $0$.
Therefore, $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{0}{O_2} = 0$.

(D) The $R.Q.$ (Respiratory Quotient) is the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed.
For carbohydrates,the $R.Q.$ is $1.0$.
For fats,the $R.Q.$ is approximately $0.7$.
For proteins,the $R.Q.$ is approximately $0.9$.
For organic acids,the $R.Q.$ is greater than $1.0$ because they are oxygen-rich compounds.
For example,the $R.Q.$ of malic acid is $1.33$ and for oxalic acid,it is $4.0$.

(D) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
When respiratory substrates are poor in oxygen,such as fats and proteins,they require more oxygen for complete oxidation.
Consequently,the volume of $O_2$ consumed is significantly higher than the volume of $CO_2$ evolved.
Therefore,the $RQ$ value for such substances is always less than one (e.g.,$RQ$ for fats is approximately $0.7$ and for proteins is approximately $0.9$).

(B) The Respiratory Quotient $(RQ)$ is the ratio of the volume of $CO_{2}$ evolved to the volume of $O_{2}$ consumed.
$1$. For $(c) C_{18}H_{36}O_{2}$ (Fat/Stearic acid): $RQ \approx 0.7$
$2$. For $(b) C_{6}H_{12}O_{6}$ (Carbohydrate/Glucose): $RQ = 1.0$
$3$. For $(a) C_{4}H_{6}O_{5}$ (Organic acid/Malic acid): $RQ = 1.33$
$4$. For $(d) \text{Succulents (night)}$: $RQ = 0$ (due to incomplete oxidation/$CAM$ metabolism).
Arranging these values in ascending order (from lowest to highest): $0 < 0.7 < 1.0 < 1.33$.
Therefore, the order is $(d), (c), (b), (a)$.

(D) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed.
During the germination of fatty seeds,fats undergo oxidation,which results in an $RQ$ value of less than $1$ (approximately $0.7$). Therefore,Assertion $(A)$ is incorrect.
Glucose is the preferred energy fuel for cells,not fats. Therefore,Reason $(R)$ is also incorrect.
Thus,the correct option is $(D)$.

(A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
$RQ$ values help identify the respiratory substrate:
$1$. For carbohydrates,the $RQ$ is $1$ because the volume of $CO_2$ evolved equals the volume of $O_2$ consumed.
$2$. For fats and proteins,the $RQ$ is less than $1$ $(< 1)$ because they require more oxygen for oxidation relative to the $CO_2$ produced.
$3$. For organic acids,the $RQ$ is greater than $1$ $(> 1)$ because they are already oxygen-rich and produce more $CO_2$ relative to the $O_2$ consumed.

(A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during the process of respiration.
Mathematically, it is expressed as: $RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$.
This value helps in determining the type of respiratory substrate being oxidized (e.g., carbohydrates, fats, or proteins).

(A) The respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For carbohydrates, the chemical equation for complete oxidation is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{6}{6} = 1$.
Therefore, the $RQ$ for carbohydrates is $1$.

(B) The respiratory quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For proteins,the $RQ$ value typically ranges from $0.7$ to $0.9$,depending on the amino acid composition.
However,in standard biological contexts,the value $0.9$ is commonly accepted for proteins.
Therefore,the correct option is $B$.

(C) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}}$
In the given reaction: $2(C_{51}H_{98}O_6) + 145O_2 \rightarrow 102CO_2 + 98H_2O + \text{Energy}$
Number of $CO_2$ molecules evolved = $102$
Number of $O_2$ molecules consumed = $145$
$RQ = \frac{102}{145} \approx 0.7$
This reaction represents the oxidation of a fatty acid (tripalmitin), which typically has an $RQ$ of approximately $0.7$.

(B) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
In alcoholic fermentation, glucose is broken down into ethanol and carbon dioxide in the absence of oxygen:
$C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2 + \text{Energy}$
Since no oxygen is consumed $(O_2 = 0)$ and carbon dioxide is produced, the $RQ$ is calculated as:
$RQ = \frac{\text{Volume of } CO_2 \text{ evolved}}{\text{Volume of } O_2 \text{ consumed}} = \frac{2}{0} = \infty$
Therefore, the $RQ$ for alcoholic fermentation is infinity.

(A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
In lactic acid fermentation,glucose is converted into lactic acid without the consumption of $O_2$ and without the release of $CO_2$ $(C_6H_{12}O_6 \rightarrow 2C_3H_6O_3)$.
Since the volume of $CO_2$ evolved is $0$,the $RQ$ value is calculated as $0/0$,which is mathematically undefined,but in biological contexts,it is considered $0$ because no $CO_2$ is produced.

(A) The Respiratory Quotient $(RQ)$ is defined as the ratio of the volume of $CO_2$ evolved to the volume of $O_2$ consumed during respiration.
For carbohydrates, the chemical equation for aerobic respiration is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
From the equation, $6$ molecules of $CO_2$ are produced and $6$ molecules of $O_2$ are consumed.
Therefore, $RQ = \frac{6CO_2}{6O_2} = 1$.
Since the $RQ$ value is $1$ because the volume of $CO_2$ evolved is equal to the volume of $O_2$ consumed, the Reason correctly explains the Assertion.