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Milislav Demerec
Milislav Demerec (January 11, 1895 – April 12, 1966) was a Croatian- American geneticist, and the director of the Department of Genetics, Carnegie Institution of Washington IW now Cold Spring Harbor Laboratory (CSHL) from 1941 to 1960, recruiting Barbara McClintock and Alfred Hershey. Demerec was born and raised in Kostajnica (then Austria-Hungary, now Croatia). He attended College of Agriculture in Križevci, graduating in 1916. He worked at Krizevci Experiment Station, and then attended the College of Agriculture in Grignon, France after World War I. He emigrated to the United States for graduate studies in 1919. In 1919 he started his PhD at Cornell University, his work was on maize genetics and was supervised by Rollins A. Emerson. He completed his PhD in 1923 and took up a research position at the Carnegie Institution of Washington's IWDepartment of Genetics, now Cold Spring Harbor Laboratory. He completed work from his PhD, showing that ten different alleles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hrvatska Kostajnica
Hrvatska Kostajnica (; ; ), also referred to as simply Kostajnica, is a town in central Croatia. It is located on the Una (Sava), Una river in the Sisak-Moslavina County, south of Petrinja and Sisak and across the river from Kostajnica, Bosnia and Herzegovina, Kostajnica in Bosnia and Herzegovina. In the past, Hrvatska Kostajnica was called by different names, Koztainicha, Kaztanicha to Costgnanica. The name most likely comes from the word Kostanj (chestnut). Climate Since records began in 1981, the highest temperature recorded at the local weather station was , on 18 July 2007. The coldest temperature was , on 13 February 1985. History Middle Ages Kostajnica was first mentioned in the document by knights templar from 1240. This year is used as official birth year of this historic town. Its name is derived from the word ''kostanj'' ("chestnut"), as the nearby hills around the Una river are covered with forests of chestnut trees. Time of the first settlement is unknown, but town ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Hershey
Alfred Day Hershey (December 4, 1908 – May 22, 1997) was an American Nobel Prize–winning bacteriologist and geneticist. Early years Hershey was born in Owosso, Michigan to Robert Day and Alma Wilbur Hershey. He earned a B.S. in chemistry in 1930, and Ph.D. in bacteriology in 1934 from Michigan State University. Shortly after, Hershey accepted a faculty position at Washington University in St. Louis, serving as an instructor of bacteriology and immunology from 1934 to 1950. Bacteriophage research At Washington University, Hershey worked closely with department head Jacques Bronfenbrenner to investigate bacteriophages, or phages—viruses that infect and replicate inside bacteria. Hershey's work on the factors impacting the virus' ability to infect its targets brought him to the attention of fellow phage researchers Max Delbrück and Salvador Luria. The Phage Group In 1943, Delbrück invited Hershey to Vanderbilt University to discuss his phage research. Together, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvin Bridges
Calvin Blackman Bridges (January 11, 1889 – December 27, 1938) was an American scientist known for his contributions to the field of genetics. Along with Alfred Sturtevant and H.J. Muller, Bridges was part of Thomas Hunt Morgan's famous "Fly Room" at Columbia University. Early life Calvin Blackman Bridges was born in Schuyler Falls, New York (state), New York in 1889 to the parents of Leonard Bridges and Charlotte Blackman. Tragically, Calvin's mother died when he was two years old, and his father died a year later, leaving the young Calvin an orphan. Bridges was subsequently taken in and raised by his grandmother. It took Bridges several years to complete high school, graduating when he was 20 years old. Despite this setback, he moved on to be an outstanding student at Columbia University in New York City, which he attended both undergraduate and postgraduate school. While taking a zoology class at Columbia, Bridges met Thomas Hunt Morgan. This started a relationship which w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drosophila Melanogaster
''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly", or "banana fly". In the wild, ''D. melanogaster'' are attracted to rotting fruit and fermenting beverages, and are often found in orchards, kitchens and pubs. Starting with Charles W. Woodworth's 1901 proposal of the use of this species as a model organism, ''D. melanogaster'' continues to be widely used for biological research in genetics, physiology, microbial pathogenesis, and Life history theory, life history evolution. ''D. melanogaster'' was the first animal to be Fruit flies in space, launched into space in 1947. As of 2017, six Nobel Prizes have been awarded to drosophilists for their work using the insect. ''Drosophila melanogaster'' is typically used in research owing to its rapid life cycle, relatively simple genetics with on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaicism
Mosaicism or genetic mosaicism is a condition in which a multicellular organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized egg. Mosaicism is one of several possible causes of chimerism, wherein a single organism is composed of cells with more than one distinct genotype. Genetic mosaicism can result from many different mechanisms including chromosome nondisjunction, anaphase lag, and endoreplication. Anaphase lagging is the most common way by which mosaicism arises in the preimplantation embryo. Mosaicism can also result from a mutation in one cell during development, in which case the mutation will be passed on only to its daughter cells (and will be present only in certain adult cells). Somatic mosaicism is not generally inheritable as it does not generally affect germ cells. History In 1929, Alfred Sturtevant studied mosaicism in ''Drosophila'', a genus of fruit fly. H. J. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drosophilidae
The Drosophilidae are a diverse, cosmopolitan family of flies, which includes species called fruit flies, although they are more accurately referred to as vinegar or pomace flies. Another distantly related family of flies, Tephritidae, are true fruit flies because they are frugivorous, and include apple maggot flies and many pests. The best known species of the Drosophilidae is ''Drosophila melanogaster'', within the genus ''Drosophila'', also called the "fruit fly." ''Drosophila melanogaster'' is used extensively for studies concerning genetics, development, physiology, ecology and behaviour. Many fundamental biological mechanisms were discovered first in ''D. melanogaster.'' The fruit fly is mostly composed of post-mitotic cells, has a very short lifespan, and shows gradual aging. As in other species, temperature influences the life history of the animal. Several genes have been identified that can be manipulated to extend the lifespan of these insects. Additionally, '' Drosophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delphinium
''Delphinium'' is a genus of about 300 species of annual and perennial flowering plants in the family (biology), family Ranunculaceae, native species, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. The genus was erected by Carl Linnaeus. All members of the genus ''Delphinium'' are toxic to humans and livestock. The common name larkspur is shared between perennial ''Delphinium'' species and annual species of the genus ''Consolida''. Molecular data show that ''Consolida'', as well as another segregate genus, ''Aconitella'', are both embedded in ''Delphinium''. The genus name ''Delphinium'' derives from the Ancient Greek word () which means "dolphin", a name used in ''De Materia Medica'' for some kind of larkspur. Pedanius Dioscorides said the plant got its name because of its dolphin-shaped flowers. Habitat Species with short stems and few flowers such as ''Delphinium nuttallianum'' and ''Delphinium bicolor'' appear in habitats like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albinism
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of the terms mean that written reports of albinistic animals can be difficult to verify. Albinism can reduce the survivability of an animal; for example, it has been suggested that albino alligators have an average survival span of only 24 hours due to the lack of protection from UV radiation and their lack of camouflage to avoid predators. It is a common misconception that all albino animals have characteristic pink or red eyes (resulting from the lack of pigment in the Iris (anatomy), iris allowing the blood vessels of the retina to be visible); this is not the case for some forms of albinism. Familiar albino animals include in-bred strains of laboratory animals (rats, mice and rabbits), but populations of naturally occurring albino animals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alleles
An allele is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule. Alleles can differ at a single position through single nucleotide polymorphisms (SNP), but they can also have insertions and deletions of up to several thousand base pairs. Most alleles observed result in little or no change in the function or amount of the gene product(s) they code or regulate for. However, sometimes different alleles can result in different observable phenotypic traits, such as different pigmentation. A notable example of this is Gregor Mendel's discovery that the white and purple flower colors in pea plants were the result of a single gene with two alleles. Nearly all multicellular organisms have two sets of chromosomes at some point in their biological life cycle; that is, they are diploid. For a given locus, if the two chromosomes contain the same allele, they, and the organism, are homozygous with respect to that allele. If the alleles are differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Phenotypic trait, Trait inheritance and Molecular genetics, molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the Cell (bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize
Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native Americans planted it alongside beans and squashes in the Three Sisters polyculture. The leafy stalk of the plant gives rise to male inflorescences or tassels which produce pollen, and female inflorescences called ears. The ears yield grain, known as kernels or seeds. In modern commercial varieties, these are usually yellow or white; other varieties can be of many colors. Maize relies on humans for its propagation. Since the Columbian exchange, it has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat and rice. Much maize is used for animal feed, whether as grain or as the whole plant, which can either be baled or made into the more palatable silage. Sugar-rich varieties called sw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
