Choose the correct event occuring during fertilisation.
Choose the correct event occuring during fertilisation.
The correct option is D Spermatozoon fuses with the secondary oocyte.
Fertilisation refers to the fusion of the haploid male and female gametes to form a diploid zygote. In case of humans, the fusion takes place between the spermatozoa and the secondary oocyte. This is because the process of gametogenesis is different in both males and females.
Spermatogenesis in males begins at puberty and continues uninterrupted throughout their life. In females however, oogenesis begins early in the embryonic life. The development is paused twice.
At birth, the primary oocyte gets arrested at prophase I of meiosis. It remains suspended at this stage till puberty. At puberty, the primary oocyte completes its meiosis I and becomes secondary oocyte but gets arrested at the metaphase of meiosis II. It remains suspended at this stage till fertilisation.
During ovulation, this secondary oocyte suspended at metaphase II is released. The mature sperm (or spermatozoon) fuses with the secondary oocyte arrested at the metaphase II. After fertilisation, the secondary oocyte completes its meiosis II and forms the mature ovum.
Spermatogonia and oogonia are precursors to spermatozoa and ovum. They develop from the primordial germ cells of males and females respectively. They are diploid structures. They don’t fuse with each other.
The primary spermatocyte and spermatids are intermediate stages of the development of the spermatogonia into mature spermatozoa. They don’t take part in fertilisation.
The primary oocyte and secondary oocyte are intermediary stages of development of the oogonia into mature ovum.
Fertilisation refers to the fusion of the haploid male and female gametes to form a diploid zygote. In case of humans, the fusion takes place between the spermatozoa and the secondary oocyte. This is because the process of gametogenesis is different in both males and females.
Spermatogenesis in males begins at puberty and continues uninterrupted throughout their life. In females however, oogenesis begins early in the embryonic life. The development is paused twice.
At birth, the primary oocyte gets arrested at prophase I of meiosis. It remains suspended at this stage till puberty. At puberty, the primary oocyte completes its meiosis I and becomes secondary oocyte but gets arrested at the metaphase of meiosis II. It remains suspended at this stage till fertilisation.
During ovulation, this secondary oocyte suspended at metaphase II is released. The mature sperm (or spermatozoon) fuses with the secondary oocyte arrested at the metaphase II. After fertilisation, the secondary oocyte completes its meiosis II and forms the mature ovum.
Spermatogonia and oogonia are precursors to spermatozoa and ovum. They develop from the primordial germ cells of males and females respectively. They are diploid structures. They don’t fuse with each other.
The primary spermatocyte and spermatids are intermediate stages of the development of the spermatogonia into mature spermatozoa. They don’t take part in fertilisation.
The primary oocyte and secondary oocyte are intermediary stages of development of the oogonia into mature ovum.
