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Chromatin is a complex of DNA and protein found in eukaryotic cells. [1] The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in reinforcing the DNA during cell division , preventing DNA damage , and regulating gene expression ...
Chromatin was first discovered by Walther Flemming by using aniline dyes to stain it. In 1974, it was first proposed by Roger Kornberg that chromatin was based on a repeating unit of a histone octamer and around 200 base pairs of DNA. [1] The solenoid model was first proposed by John Finch and Aaron Klug in 1976.
The centrosome was discovered jointly by Walther Flemming in 1875 [1] [2] and Edouard Van Beneden in 1876. [3] [4] Flemming investigated the process of cell division and the distribution of chromosomes to the daughter nuclei, a process he called mitosis from the Greek word for thread. However, he did not see the splitting into identical halves ...
The term was coined by Heinrich Wilhelm Gottfried von Waldeyer-Hartz, referring to the term chromatin, was introduced by Walther Flemming. Scientists also discovered plant and animal cells have a central compartment called the nucleus. They soon realized chromosomes were found inside the nucleus and contained different information for many ...
Heterochromatin vs. euchromatin. Chromatin is found in two varieties: euchromatin and heterochromatin. [7] Originally, the two forms were distinguished cytologically by how intensely they get stained – the euchromatin is less intense, while heterochromatin stains intensely, indicating tighter packing.
Each eukaryotic chromosome consists of a long linear DNA molecule associated with proteins, forming a compact complex of proteins and DNA called chromatin. Chromatin contains the vast majority of the DNA in an organism, but a small amount inherited maternally can be found in the mitochondria.
In 1879, Walther Flemming coined the term chromatin. [citation needed] In 1883, August Weismann connected chromatin with heredity. In 1884, Albrecht Kossel discovered histones. In 1888, Sutton and Boveri proposed the theory of continuity of chromatin during the cell cycle [8] In 1889, Wilhelm von Waldemeyer created the term "chromosome". [9]
The cell nucleus (from Latin nucleus or nuculeus 'kernel, seed'; pl.: nuclei) is a membrane-bound organelle found in eukaryotic cells.Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many.