Meaning of animal kingdom
What is Animal Kingdom:
The animal kingdom, also known in Latin as Animalia (animal) or Metazoans (metazoa), is a set of living beings that share relevant characteristics that distinguish them from others.
The animals that make up this kingdom have a great morphological and behavioral diversity, they are multicellular, eukaryotic, heterotrophic beings (that is, they feed on other living beings), their reproduction is sexual and autonomous locomotion. Therefore, animals, even humans, are very complex organisms.
Now, the animals that make up this kingdom are classified into various phyla or types of taxonomic organization, the most distinguished being the invertebrate animals (they do not have a backbone) and the vertebrates (they have a backbone and skull) which in turn belong to the phylum of the chordates.
In consideration of this point, it is important to highlight that taxonomy is the science that is applied to systematically rank and classify animal and plant groups.
See also the meaning of Taxonomy.
Characteristic of the animal kingdom
On planet Earth there are a considerable number of animals that can be differentiated thanks to the fact that they differ by species, cell composition and the diet they carry out. Among the main features are:
Eukaryotes: animals whose cells contain a defined cell nucleus due to their nuclear membrane.
Multicellular: are organisms made up of two or more cells which have specialized functions.
Heterotrophs: animals need to ingest and absorb nutrients from other living beings due to the inability to produce their own food.
Aerobes: animals breathe, even through their skin, the oxygen they obtain from the environment (water, air, soil), which are the spaces where they develop.
Reproduction: animals reproduce sexually, so there are sex cells called male and female. However, there are some invertebrates whose reproduction is asexual, that is, through mitosis.
Development: animals can develop and be born in different ways depending on their species. Some animals are oviparous (they develop and hatch from eggs), viviparous (they develop and hatch directly from the mother), and ovoviviparous (the eggs remain inside the female until birth).
Tissues and organs: refers to the fact that animals have cellular tissues that differ and specialize, hence living beings have skin, muscles, organs, nerve endings, digestive system and nervous system, among others.
Symmetry: there are animals that are symmetrical and others are not, this depends on their physical structure. For example, human beings have a bilateral symmetry, that is, two sides, left and right.
There is also radial symmetry that is characterized because all the sides are symmetrical starting from the center of the animal. However, there are other animals that do not have symmetry, for example, the sea sponge.
Classification of the animal kingdom
The classification of animals splits two important groups, vertebrates and invertebrates.
Vertebrate animals are those that have vertebrae and their number is lower with respect to invertebrate animals. These animals are part of the chordate phylum and are divided into 5 classes, namely that they are:
Fish: live in water, breathe through gills, are oviparous and have cold blood.
Amphibians: they are quadruped and some have tails. They live near water, are oviparous and have cold blood.
Reptiles: they have lungs to breathe, they are cold-blooded and oviparous.
Birds: they have four limbs (two wings and two legs), although they have wings, not all of them can fly. They are warm-blooded and oviparous.
Mammals: they have four limbs, they are warm-blooded, they are born from the mother's womb.
Invertebrate animals are characterized by lacking vertebrae or bones, being multicellular and outnumbering vertebrate animals.
Coelenterates: jellyfish and polyps.
Worms: annelids, nematodes and flatworms.
Echinoderms: stars and sea urchins.
Mollusks: cephalopods, bivalves and gastropods.
Arthropods: insects, arachnids, crustaceans and myriapods.
Animal kingdom and plant kingdom
The plant kingdom, also known by its scientific name plant, is characterized by autotrophic organisms (which produce their own food), that is, by means of sunlight they carry out the process of photosynthesis, and in turn feed heterotrophic organisms of the animal kingdom, fungi and bacteria.
See also Animal and plant cell.
Plants, algae, flowers, fruits, bushes, seeds, among others, are part of the plant kingdom.
The plant kingdom is also essential for human life, provides food and fabrics for clothing, as well as provides wood for the construction of houses, among others.