Plants are known as purifiers of air due to the process of:

If $CO_2$ is released during respiration,why does the concentration of $CO_2$ in the atmosphere remain relatively constant?

The plant $Cuscuta$ shows maximum photosynthesis in

Photosynthesis takes place in:

In submerged hydrophytes,the entry of $CO_2$ is through:

Read the following and choose the option containing the correct pair:
$I.$ $DCMU$: Herbicide,Inhibitor of non-cyclic electron transport
$II.$ $PMA$: Fungicide,Reduces transpiration
$III.$ Colchicine: Alkaloid,Causes male sterility
$IV.$ Soilrite: Sodium alginate,Encapsulation of somatic embryos