Practice question

Micropyle originates from narrow gap between integuments of ovule persisting in mature seed coat as minute pore near hilum. During germination it serves as primary portal for water imbibition initiating metabolic reactivation, enzyme synthesis like amylases, respiration increase and radicle expansion through testa. It previously allowed pollen tube entry into embryo sac during fertilization. Gas exchange occurs through general testa porosity and hilum, food storage in endosperm or cotyledons, protection by testa and tegmen. Micropylar function is critical for dormancy break demonstrated by increased germination after micropylar scarification in hard-seeded species.