Answer:
3. Medusa buttons. Medusa buttons.
4. Meiosis occurs. Meiosis occurs.
5. Fertilization takes place. Fertilization takes place.
6. The cells grow in Planula.
1. Form of reproductive polyps.
2. Growth in mature polyp Form of reproductive polyps.
Explanation:
The Obelia life cycle begins when two jellyfish buttons of opposite sexes undergo meiosis forming the female and male gametes. The male gamete will fertilize the female gamete, forming a zygote. The cells of the zygote will grow into a structure called Planula that will develop and form a mature popolis (a structure that looks like a stem with roots that hold it to the rocky part of the ocean), the mature propolis means that it is able to reproduce itself. if so, it will form reproductive propolis.
Question:
Give the order for the life cycle of the hydrozoan, Obelia, starting with the reproductive polyp form.
1. Reproductive polyps form.
2. Growth into mature polyp Reproductive polyps form.
3. Medusa buds.
4. Meiosis occurs.
5. Fertilization occurs.
6. Cells grow into Planula.
Answer:
The order for the lifecycle of the hydrozoan - Obelia starting from the reproductive polyp form is given below:
3. From Reproductive form of the Polyph, it sheds the Medusa buds. The medusa stage of Obelia species is common in coastal and offshore plankton around the world. The blastostyles of the Polyph are the reproductive zooids as they reproduce asexually to give rise to numerous lateral buds called medusa buds or gonophores. These buds develop into third type of zooids of the colony called medusae.
5 After medusa happens, Fertilisation occurs: Sometimes the flagellated sperms swim about in water and fertilize the ova present in female medusae. The fertilisation takes place in water. As medusa is the motile form, it performs two important functions for the colony namely reproduction and dispersal of the gametes.
4. After fertilisation then Meiosis starts to happen. Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females. During meiosis one cell divides twice to form four daughter cells.
6. After meiosis, cells grow into Planula.
The embryo is set free from the egg membrane as a free-swimming larva called the planula. The larva swims about for some time and brings about wide distribution of the species.
After the free-swimming life the planula larva loses its cilia and settles down on the bottom of the sea, gets attached to the substratum by its broader end and undergoes metamorphosis.
1. Reproductive Polyps begin to form.
2. Growth into mature polyp Reproductive polyps form: the Obelia achieves full maturity and ready for the cycle all over again.
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