Cell Shape IMG_20240406_0008.pdf

, Conttactile vacgole water glcbules.,.1. '.':':'. The basic shape of eukarr-otic cell is spherical, but the shape of ceil is uitimatelv determined by the specific function ci the cell. Thus, the shape of the ce11 marbe variable (i.e., frequently changing rts shape) of fixed. Varinble or irregular s...

, Conttactile vacgole water glcbules.,.1. '.':':'. The basic shape of eukarr-otic cell is spherical, but the shape of ceil is uitimatelv determined by the specific function ci the cell. Thus, the shape of the ce11 marbe variable (i.e., frequently changing rts shape) of fixed. Varinble or irregular sirape occurs in Amoeba (Figure 9) and lr,hite blood cells or leucocytes. In fact, leucocytes are sphericai in circulatirrg blood, but in other r--onditions thev may produce pseudopodia and become irregular in shape. Fixed shape of n.:cie.:s iood vacuoles hyalin€ cap uroid ectoplasmic ridges crystals Blasma membrane ectoplasm endoplasm Amoeba showing its irregular body shape in most plants and animals (including Euglena and Parnntecium).In unicellular organisms, the cell shape is maintained by tough plasma membrane (e.g., Paramecium) and exoskeleton (e.g., Elphidium or polystomella). In multicellular organisms, the shape of a cell depends mainly on its functional adaptations and partly on the surface tension, viscosity of the protoplasm, the mechanical action exerted by adjoining cells and rigidity of the cell membr ane (e.g., presence of rigid cell wall in plant cells). Thus, cells may have diverse shapes such as polyhedral (with 8,12 or L4 sides), spherical (e.g., eggs of many animals), spindleshaped (e.9., smooth muscle fibre), elongated (e.g., nerve cells), branched (e.g., chromatophores or pigment cells of skin), discoidal (e.9., erythrocytes or red blood cells) and so on (Figure 10). cel1 occurs I hurnan sperm leucocyte g0bler epithelial cell diatom DCI liver cell Ceratium fibroblast diatom ostrich egg :S - r^ o -a!l nerve cell choanoc.,le Various types.- :-.. : -. ,. -o'.'.'rng Ceratium,ostricheggandcl'o:^::.:: different shapes. ln this figure, except certain cells such as diatom,.". - -lcellsareshowingdiversityofeellsinhunranbody. The size of different ce.1s i-'r-- -:: :.'r,, r:r', broad limits. Some plant and animai celis are visible to the naked eyes. Most cel1s. :-.,---. : :" :ir€ r isrl.le onlv with a microscope, since ther.are only a few 16 The Fundom"n1"1 Urlt of Life: Cell a