What is correct for parthenium (Carrot grass)?
$(a)$ It came into India as a contaminant with imported wheat
$(b)$ It causes allergy
$(c)$ Asexual reproduction occurs in its flower
$b$ -correct
$b, c$ -correct
$a$ - correct
$a, b$ - correct
Describe internal structure of anther by mentioning about typical stamen.
In an young anther the four rows of cells which later produce pollen are called
The most resistant organic material known which makes up the outermost layer of pollen wall is
Generally in the wall of the anther lobes how many middle layers are formed