Copyright © Philip M. Parker, INSEAD. Terms of Use.
| Domain | Definition |
Health | Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane. (references) |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
Eukaryotes are organisms consisting of one or more eukaryotic cellss, the most distinctive feature of which is the presence of one or more membrane-bound nuclei. Animals, plants, fungi, and various other groups collectively referred to as Protista are all eukaryotes, varying from single-celled organisms to truly multicellular forms, in which different cells are specialized for different tasks and in general do not survive when isolated. In the three-domain system, eukaryotes are treated as one domain, referred to as the Eukaryota or Eukarya. Members of the other two domains, the Bacteria and Archaea, are microorganisms with prokaryotic cells.
Eukaryotes Scientific classification
Domain: Eukaryota Typical kingdoms
Animalia Fungi Plantae Protista
Cell structure
Eukaryotic cells are generally larger than prokaryotes, with a difference in volume on the order of a thousand times. The cell includes a variety of different structures, collectively referred to as organelles. The nucleus is characteristically surrounded by a double membrane, with pores allowing materials to pass in and out. It contains the genetic material, which is separated into a series of DNA strands called chromosomes. The remainder of the cell, called the cytosol, is supported by a cytoskeleton.
Tube- and sheet-like extensions of the nuclear membrane form the endoplasmic reticulum, or ER. This includes regions that are smooth and others that are rough, where some of the ribosomes are attached, rather than all being distributed throughout the cell as in prokaryotes. Proteins synthesized by attached ribosomes enter the ER, and are thereby distributed throughout the cell, generally budding out into vesicles. In most eukaryotes, there is also a Golgi apparatus composed of stacked vesicles where proteins are modified. There may also be various vacuoles and other structures. Collectively these make up the endomembrane system.
Various other structures occur. Aside from a few protists, all eukaryotes have mitochondria, which are involved in catabolism and in particular in using oxygen. Plants and the various lines of algae also have chloroplasts, which conduct photosynthesis. Both of these are believed to represent derived prokaryotic endosymbionts, in the case of chloroplasts probably incorporated at several different times in different groups (see perhaps endosymbiotic hypothesis). Many eukaryotes have flagella or cilia, projections of the cell surface supported by microtubules that are typically motile or sensory. These arise from basal bodies or kinetosomes, which have a characteristic structure, also found in centrioles which in some groups assist in nuclear division. A few other microtubule supported structures are found, such as the axopodia of some amoeboids.
Reproduction
Nuclear division is often coordinated with cell division. This generally takes place by mitosis, a process which allows each daughter nucleus to receive one copy of each chromosome. In most eukaryotes there is also a process of sexual reproduction, typically involving an alternation between haploid generations, where only one copy of each chromosome is present, and diploid generations, where two are present, occurring through nuclear fusion (syngamy) and meiosis. There is considerable variation in this pattern, however.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Eukaryote."
Crosswords: EUKARYOTIC CELLS |
| Specialty definitions using "EUKARYOTIC CELLS": Aphidicolin ♦ CDC2, Cell Nucleolus, Cytoskeletal Proteins ♦ Heat-Shock Proteins 70 ♦ In Situ Hybridization, Inhibitory Concentration 50 ♦ RNA, Transfer, Met ♦ Transduction, Genetic ♦ ubiquitin. (references) |
| Domain | Title |
Books |
|
Source: compiled by the editor from various references; see credits. | |
Scrabble® Enable2K-Verified Anagrams | |
| Words within the letters "a-c-c-e-e-i-k-l-l-o-r-s-t-u-y" | |
-3 letters: esoterically. | |
-5 letters: allosteric, circulates, clerkliest, cockatiels, cocksurely, cortically, crackliest, electrical, ericaceous, erotically, eucaryotes, eukaryotes, eukaryotic, kilocycles, lackluster, leukocytes, leukocytic, recollects, resolutely, rustically, saucerlike, sclerotial, secularity, societally, sterically, ultraslick. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
Hexadecimal (or equivalents, 770AD-1900s) (references)45 55 4B 41 52 59 4F 54 49 43 43 45 4C 4C 53 |
| Leonardo da Vinci (1452-1519; backwards) (references)
|
Binary Code (1918-1938, probably earlier) (references)01000101 01010101 01001011 01000001 01010010 01011001 01001111 01010100 01001001 01000011 00100000 01000011 01000101 01001100 01001100 01010011 |
HTML Code (1990) (references)E U K A R Y O T I C   C E L L S |
ISO 10646 (1991-1993) (references)0045 0055 004B 0041 0052 0059 004F 0054 0049 0043 0043 0045 004C 004C 0053 |
Encryption (beginner's substitution cypher): (references)3955453552594954433723739464653 |
| 1. Crosswords 2. Usage: Commercial 3. Anagrams 4. Orthography | 5. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
