Different steps in respiration are controlled by

Which of the following reasons explain why plants do not have specialized respiratory organs?
$I-$ Each plant part takes care of its own gas exchange needs.
$II-$ There is very little transport of gases from one plant part to another.
$III-$ The rate of respiration in plants is much slower compared to animals.
$IV-$ Plants have a higher requirement for gas exchange.
$V-$ During photosynthesis,the plant's requirement for oxygen from the atmosphere increases.
$VI-$ In large,dense plants,gases can diffuse over long distances.
$VII-$ In plants,each living cell is located very close to the plant surface.

In plants,respiration takes place

Roots of a plant when kept in a phenolphthalein-containing weak alkaline solution,decolorize it. This is due to:

Given below are two statements.
Statement $I$ - During respiration the respiratory substrate directly unite with oxygen.
Statement $II$ - The primary process of respiration consists of removal of hydrogen from the respiratory substrate.
In the light of above statements,Select the correct option given below:

Which processes take place during cellular respiration?