eläinkunnat

Eläinkunnat refers to the animal kingdom in Finnish. It is one of the major kingdoms of life, encompassing all living organisms that are multicellular, eukaryotic, heterotrophic, and typically mobile. The animal kingdom is incredibly diverse, with millions of known species and many more yet to be discovered.

Animals range in complexity from simple invertebrates like sponges and jellyfish to highly complex vertebrates such as mammals, birds, reptiles, amphibians, and fish. Key characteristics that define animals include their ability to consume other organisms for energy (heterotrophy), their lack of cell walls (unlike plants and fungi), and their capacity for movement at some stage of their life cycle. Reproduction in animals is primarily sexual, though some species can reproduce asexually.

The classification of animals is based on evolutionary relationships, with the main divisions being invertebrates and vertebrates. Invertebrates, lacking a backbone, form the vast majority of animal species and include groups like insects, arachnids, crustaceans, mollusks, and echinoderms. Vertebrates, possessing a vertebral column, are further divided into mammals, birds, reptiles, amphibians, and fish. The study of animals is known as zoology, a broad field that explores their anatomy, physiology, behavior, evolution, and ecology. Understanding the animal kingdom is crucial for comprehending the interconnectedness of life on Earth and the processes that shape ecosystems.