The acrosome of sperm secretes an enzyme called hyaluronidase at the time of fertilization.

Explanation

(1) The enzyme hyaluronidase secreated by acrosome of sperm dissolves the membranous covering of the ovum to facilitate the entry of sperm into the ovum.
(2) It is lytic enzyme causing lysis of egg membrane.
(3) Owing to this, the acrosome of sperm secretes an enzyme called hyaluronidase at the time of fertilization.