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Boys
A boy is a young male human. The term is commonly used for a child or an adolescent. When a male human reaches adulthood, he is described as a man. Definition, etymology, and use According to the ''Merriam-Webster Dictionary'', a boy is "a male child from birth to adulthood". The word "boy" comes from Middle English ''boi, boye'' ("boy, servant"), related to other Germanic words for ''boy'', namely East Frisian ''boi'' ("boy, young man") and West Frisian ''boai'' ("boy"). Although the exact etymology is obscure, the English and Frisian forms probably derive from an earlier Anglo-Frisian *''bō-ja'' ("little brother"), a diminutive of the Germanic root *''bō-'' ("brother, male relation"), from Proto-Indo-European *''bhā-'', *''bhāt-'' ("father, brother"). The root is also found in Norwegian dialectal ''boa'' ("brother"), and, through a reduplicated variant *''bō-bō-'', in Old Norse ''bófi'', Dutch ''boef'' "(criminal) knave, rogue", German ''Bube'' ("knave, rogue, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anglo-Saxon Language
Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th century, and the first Old English literary works date from the mid-7th century. After the Norman conquest of 1066, English was replaced, for a time, by Anglo-Norman (a relative of French) as the language of the upper classes. This is regarded as marking the end of the Old English era, since during this period the English language was heavily influenced by Anglo-Norman, developing into a phase known now as Middle English in England and Early Scots in Scotland. Old English developed from a set of Anglo-Frisian or Ingvaeonic dialects originally spoken by Germanic tribes traditionally known as the Angles, Saxons and Jutes. As the Germanic settlers became dominant in England, their language replaced the languages of Roman Britain: Common Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, which are known as spermatozoa, while some red algae and fungi produce non-motile sperm cells, known as spermatia. Flowering plants contain non-motile sperm inside pollen, while some more basal plants like ferns and some gymnosperms have motile sperm. Sperm cells form during the process known as spermatogenesis, which in amniotes ( reptiles and mammals) takes place in the seminiferous tubules of the testes. This process involves the production of several successive sperm cell precursors, starting with spermatogonia, which differentiate into spermatocytes. The spermatocytes then undergo meiosis, reducing their chromosome number by half, which produces spermatids. The spermatids then mature and, in animals, construct a tail, or flagellum, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygote
A zygote (, ) is a eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. In multicellular organisms, the zygote is the earliest developmental stage. In humans and most other anisogamous organisms, a zygote is formed when an egg cell and sperm cell come together to create a new unique organism. In single-celled organisms, the zygote can divide asexually by mitosis to produce identical offspring. German zoologists Oscar and Richard Hertwig made some of the first discoveries on animal zygote formation in the late 19th century. Humans In human fertilization, a released ovum (a haploid secondary oocyte with replicate chromosome copies) and a haploid sperm cell (male gamete) combine to form a single diploid cell called the zygote. Once the single sperm fuses with the oocyte, the latter completes the division of the second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
