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The celi nucleus This is the part of a living celi that contains most of the cell’s genetic materiał and Controls its activities. It may have been seen by several pioneers in microscopy but was described in detail for the first time in 1804 by Franz Bauer and named in 1831 by Robert Brown.

Chromosomes Discovered inside a celi nucleus in 1879 by the German biologist Walther Flemming, chromosomes are threadlike pieces of genetic materiał inside a celPs nucleus. They contain the genes that control the development and characteristics of living things.

Bacteria These single-celled microorganisms are found everywhere on Earth. Just 0.035 oz (1 g) of soli contains 40 million bacteria.

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Plant cells The building blocks of plants, these cells are unlike those found in animals k in that they have thick walls.

" ^ They were discovered in the % i 1650s by Robert Hooke.