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Cell Theory
In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all living organisms and also the basic unit of reproduction. Cell theory has traditionally been accepted as the governing theory of all life, but some biologists consider non-cellular entities such as viruses living organisms and thus disagree with the universal application of cell theory to all forms of life. History With continual improvements made to microscopes over time, magnification technology became advanced enough to discover cells. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, known as cell biology. When observing a piece of cork under the scope, he was able to see pores. This was shocking at the time as it was believ ...
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HeLa Cells Stained With Hoechst 33258
HeLa () is an Immortalised cell line, immortalized cell line used in scientific research. It is the oldest human cell line and one of the most commonly used. HeLa cells are durable and prolific, allowing for extensive applications in scientific study. The line is derived from cervical cancer cells taken on February 8, 1951, from Henrietta Lacks, a 31-year-old African American mother of five, after whom the line is named. Lacks died of cancer on October 4, 1951. The cells from Lacks's cancerous cervical tumor were taken without her knowledge, which was common practice in the United States at the time. Cell biologist George Otto Gey found that they could be kept alive, and developed a cell line. Previously, cells cultured from other human cells would survive for only a few days, but cells from Lacks's tumor behaved differently. History Origin In 1951, Henrietta Lacks was admitted to the Johns Hopkins Hospital with symptoms of irregular vaginal bleeding; she was subsequently t ...
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Magnifying Glass
A magnifying glass is a convex lens—usually mounted in a frame with a handle—that is used to produce a magnified image of an object. A magnifying glass can also be used to focus light, such as to concentrate the Sun's radiation to create a hot spot at the focus for fire starting. Evidence of magnifying glasses exists from antiquity. The magnifying glass is an icon of detective fiction, particularly that of Sherlock Holmes. An alternative to a magnifying glass is a sheet magnifier, which comprises many very narrow concentric ring-shaped lenses, such that the combination acts as a single lens but is much thinner. Use The convex lens of a magnifying glass can be used to produce a magnified image An image or picture is a visual representation. An image can be Two-dimensional space, two-dimensional, such as a drawing, painting, or photograph, or Three-dimensional space, three-dimensional, such as a carving or sculpture. Images may be di ... of an object. A magnify ...
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Cork Cambium
Cork cambium (: cambia or cambiums) is a tissue found in many vascular plants as a part of the epidermis. It is one of the many layers of bark, between the cork and primary phloem. The cork cambium is a lateral meristem and is responsible for secondary growth that replaces the epidermis in roots and stems. It is found in woody and many herbaceous dicots, gymnosperms and some monocots (monocots usually lack secondary growth). It is one of the plant's meristems – the series of tissues consisting of embryonic disk (incompletely differentiated) cells from which the plant grows. The function of cork cambium is to produce the cork, a tough protective material.Junikka, L. (1994) "Macroscopic bark terminology". ''IAWA Journal'' 15(1): 3–45Trockenbrodt, M. (1990) "Survey and discussion of the terminology used in bark anatomy". ''IAWA Bulletin, New Series'' 11: 141–166 Synonyms for cork cambium are bark cambium, peri-cambium and phellogen. Phellogen is defined as the meristematic ...
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Cork Micrographia Hooke
"Cork" or "CORK" may refer to: Materials * Cork (material), an impermeable buoyant plant product ** Stopper (plug), or "cork", a cylindrical or conical object used to seal a container *** Wine cork an item to seal or reseal wine Places Ireland * Cork (city) ** Metropolitan Cork, also known as Greater Cork ** Cork Airport * County Cork Historical parliamentary constituencies * Cork City (Parliament of Ireland constituency) * County Cork (Parliament of Ireland constituency) * Cork City (UK Parliament constituency) * County Cork (UK Parliament constituency) United States * Cork, Georgia * Cork, Kentucky Organisations * Cork GAA, responsible for Gaelic games in County Cork * Ye Antient Order of Noble Corks, a masonic order, also known as "The Cork" * Cork City F.C., a football club * Cork City W.F.C., a women's football club Other uses * A particular kind of trick in snowboarding and skiing. * Cork (surname) * Cork City (barony) * Cork encoding, a digital data format * ...
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Electron Microscope
An electron microscope is a microscope that uses a beam of electrons as a source of illumination. It uses electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam, for instance focusing it to produce magnified images or electron diffraction patterns. As the wavelength of an electron can be up to 100,000 times smaller than that of visible light, electron microscopes have a much higher Angular resolution, resolution of about 0.1 nm, which compares to about 200 nm for optical microscope, light microscopes. ''Electron microscope'' may refer to: * Transmission electron microscopy, Transmission electron microscope (TEM) where swift electrons go through a thin sample * Scanning transmission electron microscopy, Scanning transmission electron microscope (STEM) which is similar to TEM with a scanned electron probe * Scanning electron microscope (SEM) which is similar to STEM, but with thick samples * Electron microprobe sim ...
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Visible Light
Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively '' optical radiation''. In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity, propagation direction, frequency or wavelength spectrum, and polarization. Its speed in vacuum, , is one of the fundamental constants of nature. All electromagnetic radiation exhibits some properties of both particles and waves ...
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Wavelength
In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves), phase'' on the wave, such as two adjacent crests, troughs, or zero crossings. Wavelength is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The multiplicative inverse, inverse of the wavelength is called the ''spatial frequency''. Wavelength is commonly designated by the Greek letter lambda (''λ''). For a modulated wave, ''wavelength'' may refer to the carrier wavelength of the signal. The term ''wavelength'' may also apply to the repeating envelope (mathematics), envelope of modulated waves or waves formed by Interference (wave propagation), interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed phase velocity, wave speed, wavelength is inversely proportion ...
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Ernst Abbe
Ernst Karl Abbe (23 January 1840 – 14 January 1905) was a German businessman, optical engineer, physicist, and social reformer. Together with Otto Schott and Carl Zeiss, he developed numerous optical instruments. He was also a co-owner of Carl Zeiss AG, a German manufacturer of scientific microscopes, astronomical telescopes, planetariums, and other advanced optical systems. Personal life Abbe was born 23 January 1840 in Eisenach, Saxe-Weimar-Eisenach, to Georg Adam Abbe and Elisabeth Christina Barchfeldt. He came from a humble home – his father was a foreman in a spinnery. Supported by his father's employer, Abbe was able to attend secondary school and to obtain the general qualification for university entrance with fairly good grades, at the Eisenach Gymnasium, which he graduated from in 1857. By the time he left school, his scientific talent and his strong will had already become obvious. Thus, in spite of the family's strained financial situation, his father decide ...
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Otto Schott
Friedrich Otto Schott (1851–1935) was a German people, German chemist, glass technologist, and the inventor of borosilicate glass. Schott systematically investigated the relationship between the chemical composition of the glass and its properties. In this way, he solved fundamental problems in glass properties, identifying compositions with optical properties that approach the theoretical limit. Schott's findings were a major advance in the optics for microscopy and optical astronomy. His work has been described as "a watershed in the history of glass composition". Early life and education Schott was the son of a window glass maker, Simon Schott. His mother was Karoline Schott. From 1870 to 1873 Schott studied chemical technology at the technical college in Aachen and at the University of University of Würzburg, Würzburg and at the University of Leipzig. He earned a doctorate in chemistry at Friedrich Schiller University of Jena, specializing in glass science. His doctoral th ...
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Carl Zeiss
Carl Zeiss (; 11 September 1816 – 3 December 1888) was a German scientific instrument maker, optician and businessman. In 1846 he founded his workshop, which is still in business as Zeiss (company), Zeiss. Zeiss gathered a group of gifted practical and theoretical opticians and glass makers to reshape most aspects of optical instrument production. His collaboration with Ernst Abbe revolutionized optical theory and practical design of microscopes. Their quest to extend these advances brought Otto Schott into the enterprises to revolutionize optical glass manufacture. The firm of Carl Zeiss grew to one of the largest and most respected optical firms in the world. Birth and family Carl's father, Johann Gottfried August Zeiss (1785–1849) was born in Rastenberg, where his forefathers had worked as artisans for over 100 years. August moved with his parents to Buttstädt, a small regional capital north of Weimar, where he married Johanna Antoinette Friederike Schmith (1786–18 ...
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Anton Van Leeuwenhoek
Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch art, science and technology. A largely self-taught man in science, he is commonly known as " the Father of Microbiology", and one of the first microscopists and microbiologists. Van Leeuwenhoek is best known for his pioneering work in microscopy and for his contributions toward the establishment of microbiology as a scientific discipline. Raised in Delft, Dutch Republic, Van Leeuwenhoek worked as a draper in his youth and founded his own shop in 1654. He became well-recognized in municipal politics and developed an interest in lensmaking. In the 1670s, he started to explore microbial life with his microscope. Using single-lensed microscopes of his own design and make, Van Leeuwenhoek was the first to observe and to experiment with microbes, which he originally referred to as , or . He was the first to relatively determine t ...
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Micrographia
''Micrographia: or Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses. With Observations and Inquiries Thereupon'' is a historically significant book by Robert Hooke about his observations through various lenses. It was the first book to include illustrations of insects and plants as seen through microscopes. Published in January 1665, the first major publication of the Royal Society, it became the first scientific best-seller, inspiring a wide public interest in the new science of microscopy. The book originated the biological term '' cell''. Observations Hooke most famously describes a fly's eye and a plant cell (where he coined that term because plant cells, which are walled, reminded him of the cells of a monastery"... I could exceedingly plainly perceive it to be all perforated and porous, much like a Honey-comb, but that the pores of it were not regular .these pores, or cells, .were indeed the first microscopical pores I ever saw, and perhap ...
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