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Cell nucleus: A cell's information center, the cell nucleus is the most conspicuous organelle found in a eukaryotic cell. It houses the cell's chromosomes , and is the place where almost all DNA replication and RNA synthesis ( transcription ) occur.
The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles [1] and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell and contained within the nuclear membrane is termed the nucleoplasm .
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 .
Flagella may have hairs (mastigonemes), as in many stramenopiles. Their interior is continuous with the cell's cytoplasm. [43] [44] Centrioles are often present, even in cells and groups that do not have flagella, but conifers and flowering plants have neither. They generally occur in groups that give rise to various microtubular roots.
The cells of meristematic tissue are similar in structure and have a thin and elastic primary cell wall made of cellulose. They are compactly arranged without inter-cellular spaces between them. Each cell contains a dense cytoplasm and a prominent cell nucleus. The dense protoplasm of meristematic cells contains very few vacuoles.
Red blood cells (RBCs), referred to as erythrocytes (from Ancient Greek erythros 'red' and kytos 'hollow vessel', with -cyte translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, [1] erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O 2) to the body tissues—via ...
The idea that protoplasm of eukaryotes is simply divisible into a ground substance called "cytoplasm" and a structural body called the cell nucleus reflects the more primitive knowledge of cell structure that preceded the development of electron microscopy, when it seemed that cytoplasm was a homogeneous fluid and the existence of most sub ...
Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.