Brassica campestris Linn
$(a)$ Give the common name of the plant.
$(b)$ What do the first two parts of the name denote?
$(c)$ Why are they written in italics?
$(d)$ What is the meaning of Linn written at the end of the name?

(N/A) The common name of the plant is Mustard.
$(b)$ The first part denotes the genus (generic name),and the second part denotes the specific epithet (species name).
$(c)$ According to the rules of binomial nomenclature,scientific names are printed in italics to indicate their Latin origin.
$(d)$ Linn is the abbreviation for the scientist Carolus Linnaeus,who first described and named this plant species.