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Ruth Sager
Ruth Sager (February 7, 1918 – March 29, 1997) was an American geneticist. Sager enjoyed two scientific careers. Her first was in the 1950s and 1960s when she pioneered the field of cytoplasmic genetics by discovering transmission of genetic traits through chloroplast DNA, the first known example of genetics not involving the cell nucleus. The academic community did not acknowledge the significance of her contribution until after the second wave of feminism in the 1970s.Oakes, Elizabeth. ''International Encyclopedia of Women Scientists''. 2002. Facts on File. Her second career began in the early 1970s and was in cancer genetics; she proposed and investigated the roles of tumor suppressor genes. Life Sager was born on February 7, 1918, in Chicago, Illinois, one of three daughters of Leon B. Sager, an advertising executive, and Deborah Borovik Sager. Following Sager's birth, her mother died from the influenza epidemic of the time. Sager and her sisters, Esther and Naomi, were rai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chicago
(''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name = United States , subdivision_type1 = State , subdivision_type2 = Counties , subdivision_name1 = Illinois , subdivision_name2 = Cook and DuPage , established_title = Settled , established_date = , established_title2 = Incorporated (city) , established_date2 = , founder = Jean Baptiste Point du Sable , government_type = Mayor–council , governing_body = Chicago City Council , leader_title = Mayor , leader_name = Lori Lightfoot ( D) , leader_title1 = City Clerk , leader_name1 = Anna Valencia ( D) , unit_pref = Imperial , area_footnotes = , area_total ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast DNA
Chloroplast DNA (cpDNA) is the DNA located in chloroplasts, which are photosynthetic organelles located within the cells of some eukaryotic organisms. Chloroplasts, like other types of plastid, contain a genome separate from that in the cell nucleus. The existence of chloroplast DNA was identified biochemically in 1959, and confirmed by electron microscopy in 1962. The discoveries that the chloroplast contains ribosomes and performs protein synthesis revealed that the chloroplast is genetically semi-autonomous. The first complete chloroplast genome sequences were published in 1986, ''Nicotiana tabacum'' (tobacco) by Sugiura and colleagues and ''Marchantia polymorpha'' (liverwort) by Ozeki et al. Since then, a great number of chloroplast DNAs from various species have been sequenced. Molecular structure Chloroplast DNAs are circular, and are typically 120,000–170,000 base pairs long. They can have a contour length of around 30–60 micrometers, and have a mass of about 80†... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Public Health Service
The United States Public Health Service (USPHS or PHS) is a collection of agencies of the Department of Health and Human Services concerned with public health, containing nine out of the department's twelve operating divisions. The Assistant Secretary for Health oversees the PHS. The Public Health Service Commissioned Corps (PHSCC) is the federal uniformed service of the PHS, and is one of the eight uniformed services of the United States. PHS had its origins in the system of marine hospitals that originated in 1798. In 1871 these were consolidated into the Marine Hospital Service, and shortly afterwards the position of Surgeon General and the PHSCC were established. As the system's scope grew to include quarantine authority and research, it was renamed the Public Health Service in 1912. A series of reorganizations in 1966–1973 began a shift where PHS' divisions were promoted into departmental operating agencies. PHS was established as a thin layer of hierarchy above ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendelian Inheritance
Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularized by William Bateson. These principles were initially controversial. When Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics. Ronald Fisher combined these ideas with the theory of natural selection in his 1930 book ''The Genetical Theory of Natural Selection'', putting evolution onto a mathematical footing and forming the basis for population genetics within the modern evolutionary synthesis. History The principles of Mendelian inheritance were named for and first derived by Gregor Johann Mendel, a nineteenth-century Moravian monk who formulated his ideas after conducting simple hybridisation experiments with pea plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptomycin
Streptomycin is an antibiotic medication used to treat a number of bacterial infections, including tuberculosis, ''Mycobacterium avium'' complex, endocarditis, brucellosis, ''Burkholderia'' infection, plague, tularemia, and rat bite fever. For active tuberculosis it is often given together with isoniazid, rifampicin, and pyrazinamide. It is administered by injection into a vein or muscle. Common side effects include vertigo, vomiting, numbness of the face, fever, and rash. Use during pregnancy may result in permanent deafness in the developing baby. Use appears to be safe while breastfeeding. It is not recommended in people with myasthenia gravis or other neuromuscular disorders. Streptomycin is an aminoglycoside. It works by blocking the ability of 30S ribosomal subunits to make proteins, which results in bacterial death. Albert Schatz first isolated streptomycin in 1943 from '' Streptomyces griseus''. It is on the World Health Organization's List of Essential Medic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydomonas Reinhardtii
''Chlamydomonas reinhardtii'' is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot that senses light. ''Chlamydomonas'' species are widely distributed worldwide in soil and fresh water. ''Chlamydomonas reinhardtii'' is an especially well studied biological model organism, partly due to its ease of culturing and the ability to manipulate its genetics. When illuminated, ''C. reinhardtii'' can grow photoautotrophically, but it can also grow in the dark if supplied with organic carbon. Commercially, ''C. reinhardtii'' is of interest for producing biopharmaceuticals and biofuel, as well being a valuable research tool in making hydrogen. History The ''C. reinhardtii'' wild-type laboratory strain c137 (mt+) originates from an isolate collected near Amherst, Massachusetts, in 1945 by Gilbert M. Smith. The species' name ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sam Granick
Sam Granick (February 16, 1909 – April 29, 1977) was an American biochemist known for his studies of ferritin and iron metabolism more broadly, of chloroplast structure, and of the biosynthesis of heme and related molecules. Granick was born in New York City, and earned a B.S. (1931), M.S. (1933) and Ph.D. (1938) degrees from the University of Michigan, where he completed a dissertation in plant physiology. In 1939 Granick joined the laboratory of biochemist Leonor Michaelis at the Rockefeller Institute for Medical Research; he would remain at the Rockefeller Institute for the rest of his scientific career.Attallah Kappas and Richard D. Levere,In memoriam: Sam Granick 1909-1977, ''Blood'', volume 50, number 3, September 1977, p. 543. Between 1942 and 1946, Granick and Michaelis, along with Alexandre Rothen, published a series of important research papers on ferritin and other ferric compounds in the '' Journal of Biological Chemistry''. In the first paper, Granick showed th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in the cells. The ATP and NADPH is then used to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in unicellular algae, up to 100 in plants like '' Arabidopsis'' and wheat. A chloroplast is characterized by its two membranes and a high concentration of chlorophyll. Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are highly dynamic—they cir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Research Council (United States)
The National Academies of Sciences, Engineering, and Medicine (also known as NASEM or the National Academies) are the collective scientific national academy of the United States. The name is used interchangeably in two senses: (1) as an umbrella term for its three quasi-independent honorific member organizations the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the National Academy of Medicine (NAM); and (2) as the brand for studies and reports issued by the operating arm of the three academies, the National Research Council (NRC). The NRC was first formed in 1916 as an activity of the NAS. Now jointly governed by all three academies, the NRC produces some 200 publications annually which are published by the National Academies Press. The reports produced by the National Academies have been characterized as reflective of scientific consensus. History The US National Academy of Sciences was created by an Act of Incorporation dated March 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbara McClintock
Barbara McClintock (June 16, 1902 – September 2, 1992) was an American scientist and cytogeneticist who was awarded the 1983 Nobel Prize in Physiology or Medicine. McClintock received her PhD in botany from Cornell University in 1927. There she started her career as the leader of the development of maize cytogenetics, the focus of her research for the rest of her life. From the late 1920s, McClintock studied chromosomes and how they change during reproduction in maize. She developed the technique for visualizing maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic ideas. One of those ideas was the notion of genetic recombination by crossing-over during meiosis—a mechanism by which chromosomes exchange information. She produced the first genetic map for maize, linking regions of the chromosome to physical traits. She demonstrated the role of the telomere and centromere, regions of the chromosome that are important in the conservation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcus Rhoades
Marcus Morton Rhoades (July 24, 1903 in Graham, Missouri – December 30, 1991) was an American cytogeneticist. Education He earned a Bachelor of Science degree in 1927, a Master of Science degree in 1928 from the University of Michigan and a Ph.D. degree in 1932 from Cornell University where he was a trainee of Rollins A. Emerson alongside future Nobel Prize winners George Beadle and Barbara McClintock, and completed a thesis on the topic of cytoplasmic male sterility in maize.http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/rhoades-m-m.pdf Career After completing his doctoral studies, Rhoades's career spanned numerous institutions, first working as an experimentalist in plant breeding at Cornell University from 1932 to 1935, a research geneticist with the USDA in Ames, Iowa and later Arlington, Virginia from 1935 to 1940, an associate professor and later full professor at Columbia University from 1940 to 1948, a professor at UIUC from 1948 to 1958, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maÃz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The leafy stalk of the plant produces pollen inflorescences (or "tassels") and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds, which are fruits. The term ''maize'' is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike ''corn'', which has a complex variety of meanings that vary by context and geographic region. Maize has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat or rice. In addition to being consumed directly by humans (often in the form of masa), maize is also used for corn ethanol, animal feed and other maize products, such as corn starch and corn sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
