Developments In Frogs And Birds

Essay by PaperNerd ContributorCollege, Undergraduate May 2001

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The first main difference between a birds's egg and a frog's egg is that a frog's fertilization does not occur inside the mother, but the mother actually releases her eggs, and then they are fertilized. For birds, the eggs are already fertilized when they are released from the mother. Frogs lay their eggs in the water, while the birds lay their eggs in their nest or other secure habitat where the mother lives. Bird's eggs have hard shells for protection and are kept secure and warm because the mother usually will lie on the eggs until attached. Frogs, on the other hand, are abandoned once they are eggs. Because of this, they have their own form of protection- a jelly covering to protect it and help it stick to vegetation. Another difference is that when the bird is hatched is pretty much in full structure, while the frog still undergoes many structural changes after it has been hatched.

I think the birds have a better chance of survival primarily because of the care the parents have other them. They are covered by the mother nearly the whole day, so predators and other dangers and warded off. However, for frogs, they are on their own from the very beginning and since there are many risks, like other water animals and the currant of the water, frogs probably have less chances of survival.

Tadpoles and frogs differ in many ways. Eating habits, for example, in tadpoles are that for the first seven days of their hatching, they feed on their yolk in the stomach as well as their jelly coating. Later on, they feed on algae, other tiny bits of plants, and other organic matter. They are mainly herbivores. Frogs, however or carnivores and have a long, sticky tongue so they can catch insects with. Tadpoles and frogs are usually found in the water, but frogs are able to be out of the water for longer. Tadpoles breathe with their gills and can get rid of excess carbon dioxide through their skin. Frogs cannot inhale and exhale like we do. They fill their mouth cavity with air, close their mouth force air back through an opening called the glottis into the lungs. For tadpoles to move, they usually face the direction that they want to go in and then rapidly swing their tail back and forth in the water. Frogs have limbs, so they use them to move. They usually use their strong hind legs to jump.