Occurrence: Spermatogenesis occurs inside the seminiferous tubules of a testis whereas oogenesis occurs inside the ovary. The product form in spermatogenesis is sperm which is flagellated i.e. motile and the product form in an Oogonium is ovum which is non-motile.
Answer:C insertion of C at the start of the sequence
Explanation:
I believe it would be Heat Radiation
Its a mollusc (i think that helps?)