All organisms have organs and systems in their body that are assigned to perform specific functions. Each organism has specific organs and functions due to their environment, but some organisms share the same functions. In order for an organism to adapt to its environment, they must have the functions that are required to survive their environment. Some of the organisms that can be compared are earthworms, frogs, and fetal pigs. These organisms are similar and different in many ways. In several body systems, such as the respiratory, excretory, and integumentary systems, the organisms can be compared and contrasted. The respiratory system is required for organisms so they are able to breathe out carbon dioxide and take in oxygen. In the earthworms respiratory system, it includes simple diffusion through the skin, but it does not require gills or lungs. Earthworms breathe in from their skin since they always have moist skin. If the earthworm does not have moist skin, it will suffocate. They also breathe in their skin because they do not have a nose and their mouth is not structured for breathing. Earthworms do not have gills or lungs because it is not required since they can already breathe from their skin. The frogs respiration is simple diffusion through the skin, gills as tadpoles, lungs as adults, and trachea. The frogs breathe through their skin the same reason as the worm. They only have gills as tadpoles because they mostly grow underwater, and as they become more adult they live mostly on land. This is when they must have lungs to breathe in and out of the environment, just like humans. On top of that, the trachea because it provides a passage for inhaling air from the mouth and nostrils through the lungs. The fetal pigs respiratory system provides lungs and trachea instead of diffusion and gills. Fetal pigs do not diffuse because their skin is not always wet and moist. They do not have gills because they do not live in an aquatic environment. They need lungs and trachea, just like humans, for the same purpose as the frog.The excretory system is important for organisms because it eliminates waste that is produced from chemicals in each organisms body. The worms excretory system only requires nephridia because it fits their small body. The nephridia is located on each segment to remove waste. The frogs excretory systems include the kidneys, bladder, and cloaca. The pigs require a pair of kidneys and bladder for their excretory system. The frogs and pigs must have kidneys and bladders to filter the blood and excretes excess water and store urine. The frogs need a cloaca because it is one of their only openings for the digestive, reproductive, and urinary tracts. Fetal pigs do not have it because the male has urogenital tract and the female has urogenital papilla.Finally, all organisms have an integumentary system. This acts as a barrier to protect the body from most bacteria and diseases from entering. The worms integumentary system includes the setae, segmentation, and moist skin. The worms have segmentation which helps them move. Each segment has muscles called satea which helps anchor and control the worm when moving. Their moist skin is where the thin cuticle is to protect their skin. The frogs integumentary system includes their moistness, camouflaged skin. Their skin is moist, like the earthworm, because of a protective mucus layer, and it is camouflaged to avoid predators. Finally, the pigs integumentary system includes a thicker skin for protection, an increase of fat for warmth, and hair present for the regulation of body temperatures.In conclusion, organisms have specific body systems and organs depending on their environment and adaptation. The earthworm shared many organs in the respiratory, excitatory, and integumentary system, but they also had different organs in their body systems. This means that body systems perform similar purposes for all organisms, but they did not have to use the same organs. Each organism has organs that serve as a large impact on them due to their adaptations and their environment.