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  2. Cell envelope - Wikipedia

    en.wikipedia.org/wiki/Cell_envelope

    The bacterial cell wall differs from that of all other organisms by the presence of peptidoglycan (poly-N-acetylglucosamine and N-acetylmuramic acid), which is located immediately outside of the cytoplasmic membrane. Peptidoglycan is responsible for the rigidity of the bacterial cell wall and for the determination of cell shape. It is ...

  3. Tracheid - Wikipedia

    en.wikipedia.org/wiki/Tracheid

    A tracheid of oak shows pits along the walls. It has no perforation plates. Angiosperms have both tracheids and vessel elements. [1] A tracheid is a long and tapered lignified cell in the xylem of vascular plants. It is a type of conductive cell called a tracheary element.

  4. L-form bacteria - Wikipedia

    en.wikipedia.org/wiki/L-form_bacteria

    Although L-forms can develop from Gram-positive as well as from Gram-negative bacteria, in a Gram stain test, the L-forms always colour Gram-negative, due to the lack of a cell wall. The cell wall is important for cell division, which, in most bacteria, occurs by binary fission. This process usually requires a cell wall and components of the ...

  5. Cell wall - Wikipedia

    en.wikipedia.org/wiki/Cell_wall

    The secondary cell wall, a thick layer formed inside the primary cell wall after the cell is fully grown. It is not found in all cell types. It is not found in all cell types. Some cells, such as the conducting cells in xylem , possess a secondary wall containing lignin , which strengthens and waterproofs the wall.

  6. Protoplast - Wikipedia

    en.wikipedia.org/wiki/Protoplast

    Protoplast (from Ancient Greek πρωτόπλαστος (prōtóplastos) 'first-formed'), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall. [ 1 ] [ 2 ] Protoplasts can be generated by stripping the cell wall from plant , [ 3 ] bacterial , [ 4 ] [ 5 ] or fungal cells [ 5 ] [ 6 ] by mechanical ...

  7. Bacterial cell structure - Wikipedia

    en.wikipedia.org/wiki/Bacterial_cell_structure

    Since the cell wall is required for bacterial survival, but is absent in some eukaryotes, several antibiotics (notably the penicillins and cephalosporins) stop bacterial infections by interfering with cell wall synthesis, while having no effects on human cells which have no cell wall, only a cell membrane

  8. Trump to discuss ending childhood vaccination programs with ...

    www.aol.com/news/trump-discuss-ending-childhood...

    Trump has suggested in the past that vaccines might be linked to autism. "I want to see the numbers," he said. "At the end of the studies that we're doing, and we're going all out, we're going to ...

  9. Prokaryote - Wikipedia

    en.wikipedia.org/wiki/Prokaryote

    Diagram of a prokaryotic cell, a bacterium with a flagellum. A prokaryote (/ p r oʊ ˈ k ær i oʊ t,-ə t /; less commonly spelled procaryote) [1] is a single-celled organism whose cell lacks a nucleus and other membrane-bound organelles. [2]