Question

Explain the advantages of and disadvantages of external fertilization.

Answer 1

External fertilization is a mode of reproduction in which fertilization takes place outside of the female body. The release of eggs outside the body of organisms is known as spawning. It is carried out in frogs, fishes, etc.

Complete answer:
External fertilization is a mode of reproduction in which fertilization takes place outside of the female body. It is a common reproductive process in aquatic animals. It occurs in waters or damp areas. It is characterized by the release of both sperm and eggs into the external environment. Let’s look at some advantages and disadvantages of external fertilization.
Advantages of External Fertilization

It allows genetic variations.
Number of gametes released are greater in number which increases the chances of fertilization.
It produces a large number of offspring.
External fertilization strategies are simpler than internal fertilization.
Mother does not have to carry the offspring.
Disadvantages of External Fertilization
Offspring is not safe in external environments due to the predators and environmental hazards.
There is a possibility that eggs of the organism may not fuse with the specific organism of that species.
Large numbers of gametes are wasted as they get lost in water.
Desiccation of gametes.
Some examples of external fertilization are frogs, salmon, starfish, sea urchins, etc.
A classic example of external fertilization is of frogs.

Note: Fertilization is fusion of male gamete and female gamete in haploid state to form a diploid zygote. In humans internal fertilization takes place in the ampulla of the female fallopian tube of the female. Male gamete in humans is sperm and female gamete is ova.