1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sports, where it commonly denotes the first, leading, or top thing in a group. 1 is the unit of counting or measurement, a determiner for singular nouns, and a gender-neutral pronoun. Historically, the representation of 1 evolved from ancient Sumerian and Babylonian symbols to the modern Arabic numeral.
In mathematics, 1 is the multiplicative identity, meaning that any number multiplied by 1 equals the same number. 1 is by convention not considered a prime number. In digital technology, 1 represents the "on" state in binary code, the foundation of computing. Philosophically, 1 symbolizes the ultimate reality or source of existence in various traditions.
Twenty or 20 may refer to:
- 20 (number), the natural number following 19 and preceding 21
- one of the years 20 BC, AD 20, 1920, 2020
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). 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. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.6 m (110 ft). They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviour is known as ethology.
The animal kingdom is divided into five infrakingdoms/superphyla, namely Porifera, Ctenophora, Placozoa, Cnidaria and Bilateria. Most living animal species belong to the infrakingdom Bilateria, a highly proliferative clade whose members have a bilaterally symmetric and significantly cephalised body plan, and the vast majority of bilaterians belong to two large superphyla: the protostomes, which includes organisms such as arthropods, molluscs, flatworms, annelids and nematodes; and the deuterostomes, which include echinoderms, hemichordates and chordates, the latter of which contains the vertebrates. The much smaller basal phylum Xenacoelomorpha have an uncertain position within Bilateria.
Animals first appeared in the fossil record in the late Cryogenian period and diversified in the subsequent Ediacaran period in what is known as the Avalon explosion. Earlier evidence of animals is still controversial; the sponge-like organism Otavia has been dated back to the Tonian period at the start of the Neoproterozoic, but its identity as an animal is heavily contested. Nearly all modern animal phyla first appeared in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago (Mya), and most classes during the Ordovician radiation 485.4 Mya. Common to all living animals, 6,331 groups of genes have been identified that may have arisen from a single common ancestor that lived about 650 Mya during the Cryogenian period.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between taxa.
Humans make use of many other animal species for food (including meat, eggs, and dairy products), for materials (such as leather, fur, and wool), as pets and as working animals for transportation, and services. Dogs, the first domesticated animal, have been used in hunting, in security and in warfare, as have horses, pigeons and birds of prey; while other terrestrial and aquatic animals are hunted for sports, trophies or profits. Non-human animals are also an important cultural element of human evolution, having appeared in cave arts and totems since the earliest times, and are frequently featured in mythology, religion, arts, literature, heraldry, politics, and sports.
Deere is an English family name. It is variant spelling of Dear. This name as two possible origins, the first is derived from the Middle English (1200-1500) personal name "Dere," from the Old English pre 7th century "Deora," meaning beloved and used as a byname.
Also an Irish name derived from Dwyer.
- Alan Christopher Deere (1917-1995), New Zealand air force personnel
- Jack Deere, American pastor and theologian
- Jason Deere (born 1968), American singer-songwriter
- Jim Deere (born 1967), former American football player and coach
- John Deere (inventor) (1804-1866), American blacksmith and inventor
A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used for specialized units such as arable farms, vegetable farms, fruit farms, dairy, pig and poultry farms, and land used for the production of natural fiber, biofuel, and other biobased products. It includes ranches, feedlots, orchards, plantations and estates, smallholdings, and hobby farms, and includes the farmhouse and agricultural buildings as well as the land. In modern times, the term has been extended to include such industrial operations as wind farms and fish farms, both of which can operate on land or at sea.
There are about 570 million farms in the world, most of which are small and family-operated. Small farms with a land area of fewer than 2 hectares operate on about 12% of the world's agricultural land, and family farms comprise about 75% of the world's agricultural land.
Modern farms in developed countries are highly mechanized. In the United States, livestock may be raised on rangeland and finished in feedlots, and the mechanization of crop production has brought about a great decrease in the number of agricultural workers needed. In Europe, traditional family farms are giving way to larger production units. In Australia, some farms are very large because the land is unable to support a high stocking density of livestock because of climatic conditions. In less developed countries, small farms are the norm, and the majority of rural residents are subsistence farmers, feeding their families and selling any surplus products in the local market.
John is a common English name and surname:
- John (given name)
- John (surname)
John may also refer to:
A toy or plaything is an object that is used primarily to provide entertainment. Simple examples include toy blocks, board games, and dolls. Toys are often designed for use by children, although many are designed specifically for adults and pets. Toys can provide utilitarian benefits, including physical exercise, cultural awareness, or academic education. Additionally, utilitarian objects, especially those which are no longer needed for their original purpose, can be used as toys. Examples include children building a fort with empty cereal boxes and tissue paper spools, or a toddler playing with a broken TV remote. The term "toy" can also be used to refer to utilitarian objects purchased for enjoyment rather than need, or for expensive necessities for which a large fraction of the cost represents its ability to provide enjoyment to the owner, such as luxury cars, high-end motorcycles, gaming computers, and flagship smartphones.
Playing with toys can be an enjoyable way of training young children for life experiences. Different materials like wood, clay, paper, and plastic are used to make toys. Newer forms of toys include interactive digital entertainment and smart toys. Some toys are produced primarily as collectors' items and are intended for display only.
The origin of toys is prehistoric; dolls representing infants, animals, and soldiers, as well as representations of tools used by adults, are readily found at archaeological sites. The origin of the word "toy" is unknown, but it is believed that it was first used in the 14th century. Toys are mainly made for children. The oldest known doll toy is thought to be 4,000 years old.
Playing with toys is an important part of aging. Younger children use toys to discover their identity, help with cognition, learn cause and effect, explore relationships, become stronger physically, and practice skills needed in adulthood. Adults on occasion use toys to form and strengthen social bonds, teach, help in therapy, and to remember and reinforce lessons from their youth.
A toymaker is the name of someone who makes toys.
A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agricultural tasks, especially (and originally) tillage, and now many more. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised.
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