Question

Differentiate between chalazogamy and porogamy with respect to the entry of the pollen tube.

Answer 1

Feature	Chalazogamy	Porogamy
Definition	Entry of the pollen tube into the ovule through the chalaza (basal part of the ovule).	Entry of the pollen tube into the ovule through the micropyle (apical part of the ovule).
Pathway	The pollen tube bypasses the micropyle and enters through the chalazal region.	The pollen tube follows the natural opening (micropyle) to enter the ovule.
Occurrence	Found in some plants like Casuarina and Betula.	Most common type, seen in Angiosperms like Pea, Sunflower, etc.
Significance	It is a rare type of fertilization that ensures successful fertilization even if the micropyle is blocked or damaged.	It is the most efficient and natural pathway for pollen tube entry, ensuring direct fertilization.