Uhmm they usually use internal and external at the same time..
internal
Internal
Horses breed using a method called internal fertilization.
Earthworms use external fertilization because they release their eggs and sperm into the environment, where they can mix and fertilize externally. This method increases the chances of successful fertilization and allows for greater genetic diversity. Additionally, external fertilization prevents the need for complex reproductive organs required for internal fertilization.
Raccoons exhibit internal fertilization. This means that the male raccoon deposits sperm inside the female's reproductive tract, where fertilization of the eggs occurs. This method is typical among mammals, allowing for the development of the embryo within the female's body.
The grasshopper's method of fertilization is internal. They undergo both complete and incomplete metamorphosis.
Internal fertilization and external fertilization. Internal fertilisation means fertilize the egg inside the female's body. External fertilization is fertilize the egg after the female had lay it out. All mammals including platypus and spiny anteater do internal fertilization.
Internal fertilization and external fertilizationinternal means When the fusion of the male and female gamete occurs within the female genital tract it is called internal fertilization. This type of fertilization occurs in all terrestrial animals both oviparous and viviparous. Reptiles, Birds and mammals show internal fertilization external fertilizationThe fusiri of the gametes occurs outside the body of the animal and is common in aquatic animals. In bony fishes, frogs, echinoderms the sperms and ova are released into the water and their union occurs by Chromosome number of few chance. Since fertilization occurs outside the body of the animal externally, this method is called external fertilization.
The organism's habitat can influence its method of fertilization based on the physical conditions required for successful reproduction. For example, in aquatic environments, external fertilization is common among species that release gametes into the water for fertilization to occur. On the other hand, in terrestrial environments, internal fertilization is more prevalent to ensure protection of gametes from drying out.
External fertilization typically occurs in aquatic environments, where eggs and sperm are released into the water. This method is common in many fish and amphibian species, allowing sperm to swim to the eggs for fertilization. In contrast, internal fertilization occurs inside the body of the female, common in terrestrial animals like mammals and reptiles, where sperm fertilizes the egg within the reproductive tract.
External!External fertilization takes place in fishes. This means that the sperm cell of a male is linked together with the egg cell of a female in the external bodies of the individual fish.
Gorillas, like all mammals, undergo internal fertilization. In this process, the male gorilla's sperm fertilizes the female's egg inside her body. After fertilization, the female gorilla carries the developing embryo in her uterus until giving birth. This method is typical for most mammals, providing a protected environment for the developing offspring.