Which scientist discovered cell division? Abstract: History of the discovery of cells. Basic provisions of modern cell theory

Who was the first to discover the cage? and got the best answer

Answer from Irina Ruderfer[guru]
1665 - English physicist R. Hooke in his work “Micrography” describes the structure of cork, on thin sections of which he found correctly located voids. Hooke called these voids “pores or cells.” The presence of a similar structure was known to him in some other parts of plants.
1670s - Italian physician and naturalist M. Malpighi and English naturalist N. Grew described “sacs or vesicles” in various plant organs and showed the widespread distribution of cellular structures in plants. The cells were depicted in his drawings by the Dutch microscopist A. Leeuwenhoek. He was the first to discover the world of single-celled organisms - he described bacteria and protists (ciliates).
Researchers of the 17th century, who showed the prevalence of the “cellular structure” of plants, did not appreciate the significance of the discovery of the cell. They imagined cells as voids in a continuous mass of plant tissue. Grew viewed cell walls as fibers, so he coined the term "tissue" in analogy with textile fabric. Studies of the microscopic structure of animal organs were random and did not provide any knowledge about their cellular structure.

Answer from Alienne[guru]
Anthony van Leeuwenhoek

Answer from Polina Gavrikova[newbie]
Hook)

Answer from Pavel Khudyakov[newbie]
guk

Answer from 3 answers[guru]

Hello! Here is a selection of topics with answers to your question: Who was the first to discover the cell?

– an elementary structural and functional unit of all living organisms. It can exist as a separate organism (bacteria, protozoa, algae, fungi) or as part of the tissues of multicellular animals, plants and fungi.

History of the study of cells. Cell theory.

The life activity of organisms at the cellular level is studied by the science of cytology or cell biology. The emergence of cytology as a science is closely related to the creation of cell theory, the broadest and most fundamental of all biological generalizations.

The history of the study of cells is inextricably linked with the development of research methods, primarily with the development of microscopic technology. The microscope was first used to study plant and animal tissues by the English physicist and botanist Robert Hooke (1665). While studying a section of the elderberry core plug, he discovered separate cavities - cells or cells.

In 1674, the famous Dutch researcher Anthony de Leeuwenhoek improved the microscope (magnified 270 times) and discovered single-celled organisms in a drop of water. He discovered bacteria in dental plaque, discovered and described red blood cells and sperm, and described the structure of the heart muscle from animal tissues.

• 1827 - our compatriot K. Baer discovered the egg.
• 1831 - English botanist Robert Brown described the nucleus in plant cells.
• 1838 - German botanist Matthias Schleiden put forward the idea of ​​the identity of plant cells from the point of view of their development.
• 1839 - German zoologist Theodor Schwann made the final generalization that plant and animal cells have a common structure. In his work “Microscopic Studies on the Correspondence in the Structure and Growth of Animals and Plants,” he formulated the cell theory, according to which cells are the structural and functional basis of living organisms.
• 1858 - German pathologist Rudolf Virchow applied the cell theory in pathology and supplemented it with important provisions:

1) a new cell can only arise from a previous cell;

2) human diseases are based on a violation of the structure of cells.

Cell theory in its modern form includes three main provisions:

1) cell - the elementary structural, functional and genetic unit of all living things - the primary source of life.

2) new cells are formed as a result of the division of previous ones; A cell is an elementary unit of living development.

3) the structural and functional units of multicellular organisms are cells.

Cell theory has had a fruitful influence on all areas of biological research.

The first person to see cells was an English scientist Robert Hooke(known to us thanks to Hooke's law). IN 1665 trying to understand why Cork tree swims so well, Hooke began to examine thin sections of cork with the help of his improved microscope. He discovered that the cork was divided into many tiny cells, which reminded him of monastery cells, and he called these cells cells (in English cell means “cell, cell, cell”). IN 1675 Italian doctor M. Malpighi, and in 1682- English botanist N. Grew confirmed the cellular structure of plants. They began to talk about the cell as “a vial filled with nutritious juice.” IN 1674 Dutch master Anthony van Leeuwenhoek(Anton van Leeuwenhoek, 1632 -1723 ) using a microscope for the first time I saw “animals” in a drop of water - moving living organisms ( ciliates, amoebas, bacteria). Leeuwenhoek was also the first to observe animal cells - red blood cells And spermatozoa. Thus, by the beginning of the 18th century, scientists knew that under high magnification plants have a cellular structure, and they saw some organisms that were later called unicellular. IN 1802 -1808 French explorer Charles-Francois Mirbel established that all plants consist of tissues formed by cells. J. B. Lamarck V 1809 extended Mirbel's idea of ​​cellular structure to animal organisms. In 1825, a Czech scientist J. Purkinė discovered the nucleus of the egg cell of birds, and in 1839 introduced the term " protoplasm" In 1831, an English botanist R. Brown first described the nucleus of a plant cell, and in 1833 established that the nucleus is an obligatory organelle of the plant cell. Since then, the main thing in the organization of cells has been considered not to be the membrane, but the contents.
Cell theory the structure of organisms was formed in 1839 German zoologist T. Schwann And M. Schleiden and included three provisions. In 1858 Rudolf Virchow supplemented it with one more position, however, there were a number of errors in his ideas: for example, he assumed that cells were weakly connected to each other and each existed “on its own.” Only later was it possible to prove the integrity of the cellular system.
IN 1878 Russian scientists I. D. Chistyakov open mitosis in plant cells; V 1878 V. Flemming and P. I. Peremezhko discover mitosis in animals. IN 1882 V. Flemming observes meiosis in animal cells, and in 1888 E Strasburger - from plants.

18. Cell theory- one of the generally recognized biological generalizations that affirm the unity of the principle of the structure and development of the world plants, animals and other living organisms with cellular structure, in which the cell is considered as a common structural element of living organisms.

1. For the first time he saw and described plant cells: R. Virchow; R. Hooke; K. Baer; A. Leeuwenhoek. 2. Improved the microscope and saw single-celled organisms for the first time: M. Schleiden; A. Levenguk; R. Virchow; R. Hooke.

3. The creators of the cell theory are: C. Darwin and A. Wallace; T. Schwann and M. Schleiden; G. Mendel and T. Morgan; R. Hooke and N.G. 4. Cell theory is unacceptable for: fungi and bacteria; viruses and bacteria; animals and plants; bacteria and plants. 5. The cellular structure of all living organisms indicates: the unity of the chemical composition; diversity of living organisms; the unity of origin of all living things; unity of living and inanimate nature

Prokaryotes are organisms whose cells do not have a nucleus. Prokaryotes (from Latin pro - before, instead of and Greek karyon nucleus) are a kingdom of organisms, which includes the kingdoms of Archaea (Archebacteria) and True bacteria (Eubacteria). True bacteria include bacteria themselves and cyanobacteria (the obsolete name is “blue-green algae”). An analogue of the nucleus is a structure consisting of DNA, proteins and RNA.

Prokaryotic cells have a surface apparatus and cytoplasm, in which there are a few organelles and various inclusions. Prokaryotic cells do not have most organelles (mitochondria, plastids, endoplasmic reticulum, Golgi complex, lysosomes, cell center, etc.).

The sizes of prokaryotes usually vary between 0.2 -30 microns in diameter or length. Sometimes their cells are much larger; Thus, some species of the genus Spirocheta can reach up to 250 microns in length. The shape of prokaryotic cells is varied: spherical, rod-shaped, comma-shaped or spirally twisted thread, etc.

The surface apparatus of prokaryotic cells includes a plasma membrane, a cell wall, and sometimes a mucous capsule. Most bacteria have a cell wall made of the high molecular weight organic compound murein. This connection forms a network structure that gives rigidity to the cell wall.

In cyanobacteria, the outer layer of the cell wall includes the polysaccharide pectin and special contractile proteins. They provide forms of movement such as sliding or rotation.

The cell wall often includes a thin layer - the so-called outer membrane, which, like the plasma membrane, contains proteins, phospholipids and other substances. It provides an increased degree of protection for the contents of the cell. The cell wall of bacteria has antigenic properties.

The mucous capsule consists of mucopolysaccharides, proteins or polysaccharides with protein inclusions. It is not very tightly bound to the cell and is easily destroyed by certain compounds. The surface of the cells of some bacteria is covered with numerous thin thread-like projections. With their help, bacterial cells exchange hereditary information, adhere to each other or attach to the substrate.

Ribosomes in prokaryotes are smaller than ribosomes in eukaryotic cells. The plasma membrane can form smooth or folded invaginations into the cytoplasm. The folded membrane invaginations contain respiratory enzymes and ribosomes, and the smooth ones contain photosynthetic pigments.

In the cells of some bacteria (for example, purple bacteria), photosynthetic pigments are located in closed sac-like structures formed by invaginations of the plasma membrane. Such bags can be located singly or collected in groups. Such formations of cyanobacteria are called thylakoids; they contain chlorophyll and are located singly in the surface layer of the cytoplasm.

Some bacteria and cyanobacteria that inhabit water bodies or soil capillaries filled with water have special gas vacuoles filled with a gas mixture. By changing their volume, bacteria can move through the water column with minimal energy expenditure.

Many true bacteria have one, several, or many flagella. Flagella can be several times longer than the cell itself, and their diameter is insignificant (10 -25 nm). The flagella of prokaryotes only superficially resemble the flagella of eukaryotic cells and consist of a single tube formed by a special protein. Cyanobacterial cells lack flagella.

Features of the life processes of prokaryotes § Prokaryotic cells can absorb substances with only a small molecular weight. Their entry into the cell is ensured by the mechanisms of diffusion and active transport. § Prokaryotic cells reproduce exclusively asexually: dividing in two, occasionally by budding. Before dividing, the cell's hereditary material (DNA molecule) doubles.

Tolerance of unfavorable conditions by prokaryotes When unfavorable conditions occur, sporulation occurs in some prokaryotes. Some prokaryotes are capable of encysting (from Latin in - in, inside and Greek cystis - bubble). In this case, the entire cell is covered with a dense membrane. Prokaryotic cysts are resistant to radiation and drying, but, unlike spores, are unable to withstand exposure to high temperatures. In addition to surviving unfavorable conditions, spores and cysts ensure the spread of prokaryotes with the help of water, wind or other organisms.

Let's draw conclusions § Prokaryotic cells do not have a nucleus and many organelles (mitochondria, plastids, endoplasmic reticulum, Golgi complex, lysosomes, cell center, etc.). Prokaryotes are unicellular or colonial organisms. § The surface apparatus of prokaryotic cells includes a plasma membrane, a cell wall, and sometimes a mucous capsule located above it. The cell wall of most bacteria contains the high molecular weight organic compound murein, which gives it rigidity. § The cytoplasm of prokaryotes contains small ribosomes and various inclusions. The plasma membrane can form smooth or folded invaginations into the cytoplasm. Respiratory enzymes and ribosomes are located on folded membrane invaginations;

Let's draw conclusions § In prokaryotic cells there are one or two nuclear zones, nucleoids, where the hereditary material is located - the circular DNA molecule. § The cells of some bacteria have organelles of movement: one, several or many flagella. § Prokaryotic cells reproduce by fission in two, and occasionally by budding. For some species, the process of conjugation is known, during which cells exchange DNA molecules. Spores and cysts ensure prokaryotes survive unfavorable conditions and spread in the biosphere.

People learned about the existence of cells after the invention of the microscope. The very first primitive microscope was invented by the Dutch glass grinder Z. Jansen (1590), by connecting two lenses together.

The English physicist and botanist R. Hooke, having examined a section of cork oak, discovered that it consists of cells similar to honeycombs, which he called cells (1665). Yes, yes... this is the same Hooke, after whom the famous physical law is named.

The nucleus was first discovered in plant cells by the English biologist R. Brown (1833).

Later in cell theory new discoveries were added. In 1858, the German scientist R. Virchow substantiated that all cells are formed from other cells through cell division: “every cell is from a cell.”

The cell theory served as the basis for the emergence in the 19th century. science of cytology. By the end of the 19th century. Thanks to the increasing sophistication of microscopic technology, the structural components of cells and the process of their division were discovered and studied. The electron microscope made it possible to study the finest cell structures. An amazing similarity was discovered in the fine structure of cells of representatives of all kingdoms of living nature.

• cell is a structural and functional unit of all living organisms, as well as a unit of development;
• cells have a membrane structure;
• nucleus - the main part of a eukaryotic cell;
• cells reproduce only by division;
• The cellular structure of organisms indicates that plants and animals have the same origin.