The branch of science which deals with study of pollen is known as

Solution (By Examveda Team)

The branch of science that deals with study of pollen are known as Palynology.
Palynology is the study of plant pollen, spores and certain microscopic plankton organisms.
The term is commonly used to refer to a subset of the discipline, which is defined as "the study of microscopic objects of macromolecular organic, not capable of dissolution in hydrochloric or hydrofluoric acids".