https://en.wikipedia.org/wiki/Animal
Do all animal species have two lungs and two kidneys similar to human beings?
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Do all animal species have two lungs and two kidneys similar to human beings?
No. Lungs are a feature of tetrapods (land vertebrates) and some lungfish. Many fish have swim bladders, which are thought to be homologous to lungs (they evolved from the same ancestral structure) but are not lungs, and I don't think they come in pairs anyway. Some other air-breathing organisms evolved air-breathing structures that also get called "lungs" but they are not related to human lungs, like spider "book lungs", and those don't necessarily come in pairs either (for example, spiders can have apparently one to four such lungs).
Kidneys are an organ specific to vertebrates.
It's worth noting that even the concept of having "two X" is specific to bilaterians, which is animals that show left-right symmetry. That includes all your vertebrates and insects and worms and squids and such, but it does not include animals like jellyfish, sponges or corals. You also have animals that are in the bilaterian family, and do have left-right symmetry in some life stages, but don't in others, like starfish and sea urchins.
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– MattDMo
Oct 22 '20 at 16:34