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All Stories. Series. Animals. Charlotte, the 'virgin birth' stingray, has a disease. Read. Animals. See how billions of cicadas are taking over the U.S. this summer. Read. Animals. Do...
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia ( / ˌænɪˈmɑːliə / [4] ). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development.
- Overview
- The animal kingdom
Animals are multicellular eukaryotes whose cells are bound together by collagen. Animals dominate human conceptions of life on Earth because of their size, diversity, abundance, and mobility. The presence of muscles and mobility is one of the primary characteristics of the animal kingdom.
What are the two major groups of animals?
The two major groups of animals are vertebrates and invertebrates. Vertebrates have backbones, and invertebrates do not.
When did animals first appear?
Animals first appeared in the Ediacaran Period, about 635 million to 541 million years ago, as soft-bodied forms that left traces of their bodies in shallow-water sediments.
What are the basic functional systems of animals?
Animals evolved from unicellular eukaryotes. The presence of a nuclear membrane in eukaryotes permits separation of the two phases of protein synthesis: transcription (copying) of deoxyribonucleic acid (DNA) in the nucleus and translation (decoding) of the message into protein in the cytoplasm. Compared to the structure of the bacterial cell, this ...
Animal Pictures and Facts. Learn all you wanted to know about animals with pictures, videos, facts, news, and more. Composite photograph by Joel Sartore, National Geographic Photo Ark.
See lists of animals that start with every letter of the alphabet, from A to Z. We track all types of animals like lions and tigers, dogs and cats, even dinosaurs and spiders. Choose your favorite letter below to see all animals that start with it today.
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May 27, 2024 · The Smithsonian's National Zoo is home to more than 2,200 animals representing almost 400 different species. Learn more about animals, exhibits, conservation and education at the Zoo!
Mammals are among the most adaptable animals on the planet. They are found on every continent and in every ocean, and range in size from tiny bumblebee bats to enormous blue whales.
