Dear Student,
Secondary oocytes are the immature ovum that are formed by Meiosis I in oogenesis. Thus, it has only one pair of chromosome this means it is haploid. So, it continues the second stage of meiosis, i.e Meiosis II and produces daughter cells namely, an ovum and one polar body.
Hence, during fertilization, the secondary oocyte develops into an ovum.
Regards