Question
Question: Write any four differences between external fertilization and internal fertilization....
Write any four differences between external fertilization and internal fertilization.
Solution
Fertilization is the process of fusion of the male gamete with the female gamete which results in the production of a zygote. Based on the site of fusion, that is whether it occurs outside the female body or inside the female body, it is classified into two types.
Complete answer:
| External fertilization | Internal fertilization |
|---|---|
| This type of fertilization takes place outside the body of the female. | This type of fertilization takes place inside the body of the female. |
| A huge amount of gametes gets released in the surrounding where fertilization takes place and also results in the production of many offsprings. | The male gamete gets released into the female body with the help of a copulatory organ and the process is known as copulation. Here only a few offspring are produced. |
| It requires water as a medium for the sperms to get united with the egg. | It does not require water as a medium. |
| The organisms undergoing external fertilization either live in water or return to the water for the process of reproduction. For example Algae, Fish, and Amphibians. | The organisms undergoing internal fertilization completely transitioned to life on land. For example Reptiles, Birds, Mammals, Tracheophytes, and Pteridophytes. |
Additional information:
- This process of fertilization includes the union of sperm with the egg that forms an embryo.
- The origin of meiosis is responsible for the evolution of fertilization as both of the processes are related to sexual reproduction which originates in the eukaryotic organisms.
- In plants, different families have occupied different methods of fertilization.
- The fertilization of the sperm and the egg takes place in the archegonium in bryophytes.
- Animals use two modes of fertilization based on their method of birth.
- Oviparous animals that lay eggs reproduce via internal fertilization and viviparous animals also obtain an internal method of fertilization in some cases.
- Oviparous animals also use external fertilization for or the transmission of bodily fluids which leads to greater genetic variety and minimal contact.
Note:
- The whole number of eggs is synthesized in the human female body when she is in the womb itself. This number of eggs gets reduced to half after puberty and left with only 400 during her life which gets released by ovulation.
- In the case of internal fertilization rate of successful fertilization is high whereas it is low in the case of external fertilization.
- The chances of survival of offspring are high in the case of internal fertilization because they are nourished by their parents but it is low in the case of external fertilization because there is a lack of parental care.