Difference Between Internal And External Fertilization with Examples

The difference Between Internal And External Fertilization is important for the NEET exam. Internal vs External Fertilization is part of many chapters when it comes to the NEET syllabus . Internal and external fertilization are both ways that sperm and egg come together. Internal fertilization happens when the sperm and egg join inside the female’s body. In contrast, external fertilization occurs outside the female’s body. The article below explains the differences between internal and external fertilization, gives examples, and provides more details.

What is Internal Fertilization?

Internal fertilization is a process where sperm and egg come together inside a female's body. This is different from external fertilization, where they meet outside the body. In internal fertilization, the male delivers sperm into the female’s reproductive system in various ways, like mating.

This provides a safe environment for the developing embryo, protecting it from predators and harsh conditions. Because of this, internal fertilization usually results in more successful fertilization and better chances for the young to survive. This method is common in many animals, including mammals, reptiles, birds, and some amphibians.

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What is External Fertilization?

External fertilization is a process where sperm and egg come together outside an organism's body. This is different from internal fertilization, where they meet inside the female’s reproductive system. In external fertilization, both males and females release their sperm and eggs into the environment, usually water. The sperm swim to find and fertilize the eggs.

This method is common in animals that live in water, like fish, amphibians, and many invertebrates. Although it can produce many offspring, it also makes them more vulnerable to predators and tough conditions, resulting in lower survival rates compared to internal fertilization.

Difference Between Internal And External Fertilization

NEET aspirants can study the difference between internal and external fertilization to learn more about the process. The difference between internal and external fertilization are outlined in the table below:

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Internal And External Fertilization Examples

Internal And External Fertilization Examples are as follows:

External Fertilization: External fertilization happens in water. Here, both eggs and sperm are released into the water, allowing fertilization to take place outside the body. This method is common in many fish, amphibians, and some invertebrates.

Examples of External Fertilization:

• Fish: Many fish, like salmon, spawn by having the female release eggs into the water while the male releases sperm nearby.
• Amphibians: Frogs are a good example. When they mate, the male frog holds onto the female and releases sperm over the eggs as she lays them in the water.
• Invertebrates: Sea urchins and corals also use this method. They release their eggs and sperm into the water, where fertilization happens.

Internal Fertilization: Internal fertilization occurs when sperm is deposited inside a female's body, where it fertilizes the eggs. This method is common in land animals and some aquatic species.

Examples of Internal Fertilization:

• Mammals: Humans, dogs, and cats all use internal fertilization. The male deposits sperm inside the female’s body, where it meets the egg.
• Birds: Birds, such as chickens, also use this method. The male transfers sperm to the female, and fertilization occurs inside her body before she lays the egg.
• Reptiles: Many reptiles, like snakes and lizards, also use internal fertilization. The male deposits sperm inside the female, fertilizing the eggs.

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