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The blue whale (Balaenoptera musculus) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33.6 metres (110 ft) long. The largest extant terrestrial animal is the African bush elephant (Loxodonta africana), weighing up to 12.25 tonnes and measuring up to 10.67 metres (35.0 ft) long.
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- The animal kingdom
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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 ...
Learn about the kingdom Animalia, which includes all multicellular organisms with muscles and mobility. Explore the diversity, behaviour, and history of animals, from sponges to whales, with Britannica.
Explore the fascinating world of animals with National Geographic. Find stories, photos, news, and videos about wildlife, conservation, and science.
Learn about any animal using the search box or browse the alphabetical list of animals from A to Z. Discover fascinating facts, see amazing photos, and watch videos of the world's creatures.
Animalia is a website that lets you explore and learn about the diversity of the animal kingdom. You can browse by taxonomy, habitat, diet, lifestyle, conservation status, and more, or see featured and endangered animals.
Explore the diversity and wonder of animals with photos, videos, news, and stories from National Geographic. Discover the Photo Ark project, a multiyear effort to capture every species in captivity.
Animal. Animals (or Metazoa) are living creatures with many cells. Animals get their energy from other living things. Usually, they eat them or are parasites. Animals, plants, fungi, and some other living things have complex cells, so they are grouped together as eukaryotes . The study of animals is called zoology.
