Aerobic respiration produces ......... energy from glucose. (in $kcal$)

Analogy type questions:
$(1)$ For gas exchange in animals : Specialized organs :: In plants : .......
$(2)$ During aerobic respiration in animals : $CO_2$,water,and energy :: During anaerobic respiration : .....

Write the full forms of the following abbreviations:
$(1)$ $RQ$
$(2)$ $TCA$

$A$ student has taken a twig from a plant. She/he observes a droplet of fluid exuding from the cut surface of the twig. What is this fluid?

Assertion $A$: Carbohydrates are the primary source of energy in living organisms.
Reason $R$: Glucose is the common substrate used in respiration.
Which option is correct for Assertion $A$ and Reason $R$?

Ganong's respiroscope is used to demonstrate........