Stomatal index $(I)$ is equal to:

Read the following statements carefully and choose the right answer from the codes given below:
$I$. $PMA$ and silicon oil of low viscosity are considered as antitranspirants.
$II$. $BAP$,$NAA$,and cobalt chloride are also used as antitranspirants.
$III$. Abscisic acid $(ABA)$ affects the mechanism of opening and closing of stomata.
$IV$. Starch of guard cells is converted into $PEP$ (phosphoenolpyruvate) ions by the process of hydrolysis.
$V$. Potometer works on the principle of potential difference between the tip of the tube and that of the plant.
$VI$. Transpiration rate is directly proportional to the relative humidity.

What is the stomatal apparatus? Explain the structure of stomata with a labelled diagram.

The pulling force in the plant body that develops at the top of a tree is caused by:

Stomata when open lead to:

Observe the diagram and answer the following:
$(a)$ Identify the types of guard cells shown in $(i)$ and $(ii)$.
$(b)$ Which of these types is found in monocots and which in dicots?