Oswald theodore avery (1877~ 1955)

American bacteriologist. 1877 65438+1October 2 1 was born in Halifax, Nova Scotia, Canada, and 1955 died in Nashville, Tennessee, USA on February 20th. 1887 His father moved to new york, USA. 1904 graduated from Columbia university medical college, and then went to hoagland laboratory in Brooklyn to study and teach bacteriology and immunology. 19 13 was transferred to the affiliated hospital of Rockefeller Institute in new york and retired to 1948.

He, C. mcleod and M. McCarthy found in 1944 * * that the transforming factor of different types of pneumococci is DNA. F. Griffith, a British microbiologist, found in 1928 that mice behaved normally when injected with dead type Ⅲ pneumococcus and live type Ⅱ bacteria respectively. If they are mixed and injected, mice will die, and live and pathogenic type III pneumococci can be isolated from their bodies. Griffith speculated that there must be a transforming factor in the dead bacteria of type ⅲ, which can transform type ⅱ into type ⅲ, and this transformation can be passed on to future generations. Avery and his colleagues further isolated protein, capsular components (mucopolysaccharide) and DNA from the type III bacteria killed by high temperature, and mixed these components with the live type II bacteria respectively. It was found that only DNA can transform the live type II bacteria into type III bacteria, even if it has no capsule and is not pathogenic, it can also be transformed into capsules and pathogenic pneumococci. It is proved that the transformation factor mentioned by Griffith is deoxyribonucleic acid (DNA). This experiment proved for the first time that the genetic material is DNA, not protein. Although this discovery caused controversy and suspicion, it did promote the study of DNA until 1953 discovered the double helix structure of DNA.

I was familiar with pneumococcus in my early years and studied the immunity of pneumococcus. It is suggested that pneumococci can be classified according to their immune specificity, which is caused by polysaccharides contained in capsules of different bacteria types. Therefore, he established a sensitive test method for different types of pneumococcus.

Doctor of Law Watson

James dewey watson (1928~)

American molecular biologist. 1928 was born in Chicago on April 6th. 1947 graduated from university of Chicago with a bachelor's degree, and then went to graduate school of Indiana university for further study. 195 1 ~ 1953 received his doctorate and went to the University of Copenhagen, Denmark to study phage. 1953 returned to China. 1953 to 1955 worked at California Institute of Technology, 1955 taught at Harvard University, and successively served as assistant professor and associate professor, 196 1 promoted professor. During my stay at Harvard, I was mainly engaged in the research of protein biosynthesis. 1968, director of cold spring harbor laboratory in Long Island, new york, mainly engaged in tumor research. 195 1 to 1953 in England, in cooperation with the British molecular biologist F.H.C Crick, based on the experimental data of X-ray diffraction results of DNA crystals and the regularity of base composition in DNA molecules (Xia Jiaer's law), the theory of DNA double helix structure was put forward. They think that DNA molecule is a double helix composed of two intertwined polynucleotide chains. Both chains are right-handed helices, with the skeleton composed of deoxyribose and phosphoric acid on the outside and the base on the inside. The bases of the two chains are connected by hydrogen bonds, and adenine nucleoside (A) and thymine nucleoside (T) are always paired, while guanine nucleoside (G) and cytosine nucleoside (C) are paired, and the bases in type B DNA molecules are flat. This theory not only expounds the basic structure of DNA, but also provides a reasonable explanation for how a DNA molecule is copied into two DNA molecules with the same structure and how DNA transmits the genetic information of organisms. Watson has received basic training in biology, and he has a profound belief that DNA is the material basis of heredity, while Crick studies physics. He is familiar with the method of determining the crystal structure, and their cooperation complements each other, so he has made this great achievement. It is regarded as a revolutionary discovery in biological science and one of the most important scientific achievements in the 20th century. Watson, Crick and M.H.F Wilkins won the 1962 Nobel Prize in Physiology or Medicine for putting forward the double helix model theory of DNA.

Sen is a member of the American Academy of Sciences. He is the author of Molecular Biology of Genes (1976) and Double Helix (1968). In addition, he has won many scientific awards and honorary degrees from many universities. Crick

Francis Harry Compton Crick (19 16~)

British molecular biologist. 191937 was born in Northampton on June 8, 2006 and obtained a bachelor's degree from University of London. During the Second World War, he participated in the work of the British Navy to manufacture magnetic mines. 1947 ~ 1949 works in the singular Weiss laboratory of Cambridge University. 1949 ~ 1953, working in Cavendish Experimental Physics Laboratory of Cambridge University. During this period, he cooperated with J.D. Watson and put forward the famous DNA double helix theory. 1953 received a doctorate from Cambridge University. 1953 ~ 1954 went to work in Brooklyn Institute of Technology. Later, I returned to work in the Cambridge Molecular Biology Laboratory of the British Medical Research Council. 65438-0976, went to Salk Institute of Biology as a research professor, mainly engaged in brain research.

Crick and his colleagues put forward the idea of "triple code", that is, the genetic code consists of three nucleotides and can be translated into one amino acid. In addition, he also put forward the "Swing Hypothesis" from the perspective of stereochemistry, pointing out that when codons and anti-codons are combined, the first and second nucleotides of codons are combined with the third and second nucleotides of anti-codons in strict accordance with Watson-Crick base pairing rules, but the combination between the third nucleotide of codons and the first nucleotide of anti-codons can be "free" to some extent, such as uracil nucleoside (U) and adenine nucleoside (A). It can also be paired with guanosine (G), guanosine can be paired with cytosine nucleoside (C) and uracil nucleoside, and hypoxanthine nucleoside (I) can be paired with cytosine nucleoside, uracil nucleoside or adenine nucleoside.

Together with J.D. Watson and M.H.F Wilkins, he won the 1962 Nobel Prize in Physiology or Medicine for putting forward the theory of DNA double helix structure. He is a member of the Royal Society and wrote Molecules and People. He also won many scientific awards and honorary degrees from many universities. Darwin.

Charles robert darwin (1809~ 1882)

British biologist, the main founder of evolution. 1809 was born in Shrewsbury, England in February, 1882 died in Kent in April. 183 1 graduated from Cambridge university. On February 27th of the same year, 18, she joined the British Navy's Beagle to explore the world. She first visited Brazil and Argentina on the east coast of South America, as well as the west coast and adjacent islands, then crossed the Pacific Ocean to Oceania, then crossed the Indian Ocean to South Africa, then bypassed the Cape of Good Hope via the Atlantic Ocean and returned to Brazil, and finally arrived at 1836.

After returning to China, he insisted on sorting out a large amount of data collected during the investigation, and published investigation reports on biology and geology successively, including Diary of Investigation on Geology and Natural History of the Countries Passing by Beagle (1839), Zoology of Marine Animals of Beagle (1840 ~ 1843), and related three reports. In his geological works, he put forward the famous conclusion that atolls are formed by the sinking of the seabed and the upward accumulation of corals. The five-year travel survey prompted him to think about the origin of species. He studied a lot of evidence from all sides and gradually realized that all species actually evolved from the same ancestor. Through the examples of plant cultivation and livestock domestication, he thinks that the reason of evolution may be that nature has adopted a similar biological selection method-eliminating the inferior and preserving the superior. He also noticed that there are individual differences in the biological world; Species that adapt to the environment can thrive, and those that don't adapt may become extinct. He also borrowed from the population theory of T.R. Malthus: each species has great fecundity, but only a few survive, indicating that there is fierce competition for survival in nature, resulting in a large number of deaths, thus maintaining the relative stability of the population. After years of exploration, he gradually formed a systematic evolutionary thought: there are individual differences in the biological world, and under the pressure of survival competition, the fittest survive and the unsuitable are eliminated; The favorable characteristics of species preservation gradually accumulate in the process of generation transmission, and a new species is formed after character differentiation and the disappearance of intermediate types. During the period of 1842 ~ 1844, he wrote a short article to discuss these ideas, but only showed it to a few friends. 1846, the classification of barnacle fossil species and existing species was studied, and the variation of species was deeply understood; Four monographs on tendrils were published in 185 1 ~ 1854. After that, he continued to discuss with his friends, further enriching and developing his evolutionary thought. 1On June 8th, 858, he received an article by the naturalist A.R. Wallace, in which he expressed his same views on evolution. Only at the urging of my friends did I write my own viewpoint of evolution, which was published in linnean society of london on July 1 day together with Wallace's article. Their articles did not attract general attention at that time. 1October 24th, 1859, 165438+ published his Origin of Species, in which he introduced in detail the abundant evidence collected in recent 20 years, fully demonstrated the evolution of organisms, and clearly put forward the theory of natural selection to explain the evolution mechanism. The book sold out immediately after its publication, causing great repercussions in the society. The emergence of the theory of evolution has given a unified explanation to various phenomena in the biological world: the consistency of organisms can be explained by the same ancestor; The diversity of species is the result of evolutionary adaptation. The emergence of evolution has also had a great influence in the fields of philosophy and social sciences; It violently impacted the theological concept that dominated the ideological field at that time.

Since then, Darwin's works have mostly further explained and developed the theory of evolution. For example, 1868' s Variation of Animals and Plants at Home discusses the problem of artificial selection; 187 1 year The origin and sexual selection of human beings extended the theory of evolution to human beings. In addition, there are a series of works on many adaptation phenomena in the plant kingdom, such as 1862 insect attraction and pollination strategies of orchids, 1865 movement and habits of climbing plants, 1875 insect-eating plants, 1877 cruciferous flowers in the plant kingdom, etc. The Expression of Man and Animals published by 1872 can be regarded as the earliest book about behavior. 188 1 year "the influence of earthworms on the formation of garden soil" is a pioneering work of soil ecology. He also studied the movement of plants towards light and the earth, and concluded from experiments that there is something in plants that can transmit information. Predicted the auxin found later.

mendel

Gregor Johann Mendel (1822~ 1884)

Austrian geneticist and founder of genetics. 1822 was born in Heintzen (now Heinz, Czech Republic) on July 22nd, and 1884 died in Bryan (now Brno, Czech Republic) on1October 6th. He graduated with honors from the preparatory school in Trobao in 1840, that is, he entered Olmi Tze Zhe College. 1843 drop out of school because of poverty; In the same year, he became a monk in Augustine Monastery from June to 10 in 5438. 1847 was appointed as a priest. 1849 was appointed as a substitute teacher of Greek and mathematics in Naeem Middle School. 185 1 ~ 1853 went to Vienna university to study physics, chemistry, mathematics, zoology and botany. During this period, he was influenced by the mathematics and statistics of the famous physicist J.C. Doppler, the variable species written by the botanist F.J.A.N, and the possibility that plants may produce new ideas through hybridization, which all affected his creativity in the future. /kloc-in the summer of 0/853, he graduated from Vienna University and returned to the monastery. From 65438 to 0854, he was assigned to Bryhn Technical School as an acting teacher of physics and natural history. He worked there for 14 years.

From 1856 to 1863, he conducted pea hybridization experiments for 8 years, and reported his research results at the Lv En Natural Science Research Society of 1865. 1866 published a paper entitled "plant hybridization experiment" in the journal of the association. In this paper, he put forward some important concepts such as genetic factors (now called genes), dominant traits and recessive traits, and expounded their genetic laws, which were later called Mendel's law (including "separation phenomenon" and "independent distribution law"). Mendel has a very clear idea about what problems to solve in the experiment (that is, genetic laws), what materials to choose and how to analyze the results. He broke the model of vitality theory and teleology that biologists have been following in the past, and dared to learn from the particle movement in physics, that is, the random combination and separation of particles was the basic point of experimental design and analysis. In terms of experimental methods, it is contrary to the similarity and difference between parents and children. For example, the stem height and cotyledon color are regarded as independent traits, and it is assumed that individual aggregation traits are the product of random combination and separation of various independent traits. Another advantage of him is that he has not ignored the number of individuals who did not express the independent characteristics he studied in data processing. The method of test cross established by him can best illustrate his emphasis on the genetic connotation of recessive individuals. However, these findings were not taken seriously by academic circles at that time. It was not until 1900 that Mendel's law was confirmed by three botanists-Dutch H. de Fries, German C. E. Collens and Austrian E.von Cermak, and became the basis of modern genetics. Since then, Mendel has also been recognized as the founder of scientific genetics.

In addition to plant hybridization experiments, Mendel also engaged in plant grafting and beekeeping research. In addition, he also made long-term meteorological observation and published an academic paper on the causes of the tornado in 187 1 year. He is a member of the Vienna Zoological and Botanical Society and one of the founders of the Lv En Natural Science Research Association and the Austrian Meteorological Society. M.J. Schleiden

Matthias Jacob Schleiden (1804~ 188 1)

German botanist and one of the founders of cell theory. 1804 was born in Hamburg on April 5th, and died in Frankfurt am Main on June 23rd. In his early years (1824 ~ 1827), he studied law in Heidelberg and worked as a lawyer in Hamburg. He studied botany because of his keen interest in botany, 183 1 graduated from the University of Jena. 1850 Professor of Botany, University of Jena. At that time, the popular research in botany was morphological taxonomy, and he described and named new species by studying the structure of plants under the microscope. Many scholars have described the microstructure of many animals and plants since R. Hooke called the cells in cork slices under the microscope in the17th century, but they did not introduce the concept of regularity. According to the results of his observation of plant tissue structure under the microscope for many years, Schleiden thinks that cells are the basic components of any plant structure; Lower plants are composed of single cells, while higher plants are composed of many cells. 1838 published the famous article "Botany" and put forward the above viewpoints. This paper was published in Miller's Anatomical Physiology Collection published in 1838. German zoologist T.A.H Schwann extended this concept to the animal kingdom, thus forming a scientific concept that all animals and plants are made up of cells, that is, the "cell theory", which was first published in the article "Microscopic study on the consistency between animal and plant structure and growth" written by Schwann 1839. "Cell theory" was praised by Engels as one of the three major discoveries of natural science in19th century, which greatly promoted the development of biological science. Schleiden also recognized the importance of the nucleus and observed that the nucleus is related to cell division. He also described the movement of active substances in cells, which is now called protoplasm flow movement. He was one of the first German biologists to accept Darwin's theory of evolution.

Schwann

Theodore Ambrose Hubert Schwann (18 10~ 1882)

German zoologist and physiologist. 181065438 was born in Noyce on February 7th,18821died in Cologne. He initiated modern histology and was one of the founders of cell theory. He was educated in Bonn, Wü rzburg and Berlin University. 1834 became the teaching assistant of physiologist J.P. Maitreya after receiving his doctorate.

1834 ~ 1839 is his most innovative years in scientific research. He studied the process of digestion and found pepsin, a substance related to digestion in the stomach. This is the first enzyme extracted from animal tissues. He designed an experiment to measure the change of contraction length of muscles with the same weight under the same stimulus. By comparing the contraction intensity with the stimulus intensity, he used physical methods to show physiological functions, which opened up a new quantitative way for physiological research. He realized through experiments that alcohol fermentation is related to the metabolism of yeast, and the decay of organic matter is the result of the metabolism of living organisms (microorganisms). The word "metabolism" was first used. His greatest contribution is the Microscopic Study on the Structure and Growth Consistency of Animals and Plants published in 1839. Influenced by Schleiden, a botanist, he thinks that chordal cells (or chondrocytes) are similar to plant cells, and cells are the basic units of various tissues, so different shapes are the result of cell differentiation. Therefore, although the basic units are completely different in physiology, they may develop according to the same law. He and Schleiden laid the foundation of cell theory. However, he also accepted Schleiden's wrong view that cells are formed by crystals in the matrix. After 1839, he was attacked by the authorities at that time because of the fermentation of his own views, which made him fall into a very difficult situation and was in a state of anxiety and depression for a long time. Later, L. Pasteur's experiment proved that his opinion was correct.

From 1839 to 1848, he served as a professor of physiology at the University of Leuven, developed the experimental method of bile duct, studied the role of bile in digestion, and thought that bile was indispensable in the digestive tract. From 65438 to 0848, he was a professor of physiology, anatomy and embryology at the University of Liege. He also developed a series of drainage and first aid equipment for coal mines in this increasingly prosperous industrial zone. He was still teaching physiology until 1879 retired. After middle age, he has more and more obvious religious tendencies.