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History Of Genetics
The history of genetics dates from the classical era with contributions by Pythagoras, Hippocrates, Aristotle, Epicurus, and others. Modern genetics began with the work of the Augustinian friar Gregor Johann Mendel. Experiments on Plant Hybridisation, His works on pea plants, published in 1866, provided the initial evidence that, on its rediscovery in 1900's, helped to establish the theory of Mendelian inheritance. In ancient Greece, Hippocrates suggested that all organs of the body of a parent gave off invisible "seeds", miniaturised components that were transmitted during sexual intercourse and combined in the mother's womb to form a baby. In the early modern period, William Harvey's book ''On Animal Generation'' contradicted Aristotle's biology, Aristotle's theories of genetics and embryology. The 1900 rediscovery of Mendel's work by Hugo de Vries, Carl Correns and Erich von Tschermak led to rapid advances in genetics. By 1915 the basic principles of Mendelian genetics had b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Era
Classical antiquity, also known as the classical era, classical period, classical age, or simply antiquity, is the period of cultural European history between the 8th century BC and the 5th century AD comprising the interwoven civilizations of ancient Greece and Rome known together as the Greco-Roman world, centered on the Mediterranean Basin. It is the period during which ancient Greece and Rome flourished and had major influence throughout much of Europe, North Africa, and West Asia. Classical antiquity was succeeded by the period now known as late antiquity. Conventionally, it is often considered to begin with the earliest recorded Epic Greek poetry of Homer (8th–7th centuries BC) and end with the fall of the Western Roman Empire in 476 AD. Such a wide span of history and territory covers many disparate cultures and periods. ''Classical antiquity'' may also refer to an idealized vision among later people of what was, in Edgar Allan Poe's words, "the glory that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Hunt Morgan
Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) was an Americans, American evolutionary biologist, geneticist, Embryology, embryologist, and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries elucidating the role that the chromosome plays in heredity. Morgan received his Ph.D. from Johns Hopkins University in zoology in 1890 and researched embryology during his tenure at Bryn Mawr College, Bryn Mawr. Following the rediscovery of Mendelian inheritance in 1900, Morgan began to study the genetic characteristics of the fruit fly ''Drosophila melanogaster''. In his famous Fly Room at Columbia University's Schermerhorn Hall, Morgan demonstrated that genes are carried on chromosomes and are the mechanical basis of heredity. These discoveries formed the basis of the modern science of genetics. During his distinguished career, Morgan wrote List of books by Thomas Hunt Morgan, 22 books and 370 scientific papers. As a result of his work, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theory Of Forms
The Theory of Forms or Theory of Ideas, also known as Platonic idealism or Platonic realism, is a philosophical theory credited to the Classical Greek philosopher Plato. A major concept in metaphysics, the theory suggests that the physical world is not as real or true as Forms. According to this theory, Forms—conventionally capitalized and also commonly translated as Ideas—are the timeless, absolute, non-physical, and unchangeable essences of all things, which objects and matter in the physical world merely participate in, imitate, or resemble. In other words, Forms are various abstract ideals that exist even outside of human minds and that constitute the basis of reality. Thus, Plato's Theory of Forms is a type of philosophical realism, asserting that certain ideas are literally real, and a type of idealism, asserting that reality is fundamentally composed of ideas, or abstract objects. Plato describes these entities only through the characters (primarily Socrates) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pangenesis
Pangenesis was Charles Darwin's hypothetical mechanism for heredity, in which he proposed that each part of the body continually emitted its own type of small organic particles called gemmules that aggregated in the gonads, contributing heritable information to the gametes. He presented this 'provisional hypothesis' in his 1868 work ''The Variation of Animals and Plants Under Domestication'', intending it to fill what he perceived as a major gap in evolutionary theory at the time. The etymology of the word comes from the Greek words ''pan'' (a prefix meaning "whole", "encompassing") and ''genesis'' ("birth") or ''genos'' ("origin"). Pangenesis mirrored ideas originally formulated by Hippocrates and other pre-Darwinian scientists, but using new concepts such as cell theory, explaining cell development as beginning with gemmules which were specified to be necessary for the occurrence of new growths in an organism, both in initial development and regeneration. It also accounted for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaxagoras
Anaxagoras (; , ''Anaxagóras'', 'lord of the assembly'; ) was a Pre-Socratic Greek philosopher. Born in Clazomenae at a time when Asia Minor was under the control of the Persian Empire, Anaxagoras came to Athens. In later life he was charged with impiety and went into exile in Lampsacus. Responding to the claims of Parmenides on the impossibility of change, Anaxagoras introduced the concept of '' Nous'' ( Cosmic Mind) as an ordering force. He also gave several novel scientific accounts of natural phenomena, including the notion of panspermia, that life exists throughout the universe and could be distributed everywhere. He deduced a correct explanation for eclipses and described the Sun as a fiery mass larger than the Peloponnese, and also attempted to explain rainbows and meteors. He also speculated that the sun might be just another star. Biography Anaxagoras was born in the town of Clazomenae in the early 5th century BC, where he may have been born into an aristoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristotle's Model Of Inheritance
Aristotle (; 384–322 BC) was an Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, and the arts. As the founder of the Peripatetic school of philosophy in the Lyceum in Athens, he began the wider Aristotelian tradition that followed, which set the groundwork for the development of modern science. Little is known about Aristotle's life. He was born in the city of Stagira in northern Greece during the Classical period. His father, Nicomachus, died when Aristotle was a child, and he was brought up by a guardian. At around eighteen years old, he joined Plato's Academy in Athens and remained there until the age of thirty seven (). Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored his son Alexander the Great beginning in 343 BC. He established a library in the Lyceum, which helped him to produce many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by Artificial gene synthesis, artificially synthesising the DNA. A Vector (molecular biology), construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the Lambda phage, lambda virus. As well as inserting genes, the process can be used to remove, or "Gene knockout, knock out", genes. The new DNA can either be inserted randomly or Gene targeting, targeted to a spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process (including its Regulation of gene expression, regulation) by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as Transfer RNA, transfer RNA (tRNA) and Small nuclear RNA, small nuclear RNA (snRNA), the product is a functional List of RNAs, non-coding RNA. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and viruses—to generate the macromolecule, macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, ''i.e.'' observable trait. The genetic information stored in DNA represents the genotype, whereas the phenotype results from the "interpretation" of that informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Code
Genetic code is a set of rules used by living cell (biology), cells to Translation (biology), translate information encoded within genetic material (DNA or RNA sequences of nucleotide triplets or codons) into proteins. Translation is accomplished by the ribosome, which links proteinogenic amino acids in an order specified by messenger RNA (mRNA), using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries. The codons specify which amino acid will be added next during protein biosynthesis. With some exceptions, a three-nucleotide codon in a nucleic acid sequence specifies a single amino acid. The vast majority of genes are encoded with a single scheme (see the Codon tables, RNA codon table). That scheme is often called the canonical or standard genetic code, or simply ''the'' genetic code, though #Variations, variant codes (suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Genetics
Molecular genetics is a branch of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the structure and/or function of genes in an organism's genome using genetic screens. The field of study is based on the merging of several sub-fields in biology: classical Mendelian inheritance, cellular biology, molecular biology, biochemistry, and biotechnology. It integrates these disciplines to explore things like genetic inheritance, gene regulation and expression, and the molecular mechanism behind various life processes. A key goal of molecular genetics is to identify and study genetic mutations. Researchers search for mutations in a gene or induce mutations in a gene to link a gene sequence to a specific phenotype. Therefore molecular genetics is a powerful methodology for linking mutations to genetic conditions that may aid th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Molecular Biology
The history of molecular biology begins in the 1930s with the convergence of various, previously distinct biological and physical disciplines: biochemistry, genetics, microbiology, virology and physics. With the hope of understanding life at its most fundamental level, numerous physicists and chemists also took an interest in what would become molecular biology. In its modern sense, molecular biology attempts to explain the phenomena of life starting from the macromolecular properties that generate them. Two categories of macromolecules in particular are the focus of the molecular biologist: 1) nucleic acids, among which the most famous is deoxyribonucleic acid (or DNA), the constituent of genes, and 2) proteins, which are the active agents of living organisms. One definition of the scope of molecular biology therefore is to characterize the structure, function and relationships between these two types of macromolecules. This relatively limited definition allows for the estimati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
