Cells: A Fundamental Unit of Life PDF
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This document provides an introduction to cells, describing them as the fundamental units of life. It also covers the discovery of cells by Robert Hooke and other key scientists; and the historical development of the cell theory.
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organisms) or as a part Al1 cells, whether they exists as one celled organisms (unicellular such as nutrition' of multicellular organisms are capable of carrying out certain basic functions the cells' of survival for the respiration, growth-and reproduction. These functions are essential living worl...
organisms) or as a part Al1 cells, whether they exists as one celled organisms (unicellular such as nutrition' of multicellular organisms are capable of carrying out certain basic functions the cells' of survival for the respiration, growth-and reproduction. These functions are essential living world is the cellular level' The most important and fundamental level in the organisation of and are the basic unit of Cells nre the fundnntental strttcttn'nl nttcl functional uniti of liuing organixns life. CellbioloSy is the study of cel1s in all aspects of structure and functions. *r***nc*ry* *f #*?E while studying a thin slice of cork, Robert Hooke saw that the cork resembied the is a substance structure of honeycomb consisting of manY 1ittle compartments' Cork when Hooke 1'665 year the in which is obtained from the bark of a tree. This was 1) Robert made this chance discovery through a self designed microscope (Figure Robert 1). (Box room" Hooke called these boxes - cells. Cell in Latin means "little that iiving Hooke,s discovery was important, because it indicated for the first tirne organisms consisted of a number of smaller structures or units. nifstudygear The word cell is derived from the Latin lt'ord 'cellula r,vhich means "a little room". An English scientist, Robert Hooke (1535 - 1703), in 1665 discovered and named the ceils, while examining a thin slice of bottle cork under a k flame condensers primitive microscoPe made bY him (Figure 1). Hooke observed corks honey-combed or Porous structure (Figure 2). Hooke found porous structure of cork to resemble u'ith ancl caI1er', ti-re pub1i.he.1 \ 1,. a. -r'.ts focus screw object monasteries ce11s. He units, i',ork in.l t'ook ':r l''-: Robert Hooke Robert Hooke's microscope. Figure 2' Dead cork cells as seen bY Robert Hooke. lnlbll,AntonvonLeeurgenhoek(1631- 77)3),aDutchmicroscopist,madeanimprovedmicroscope water for the first time (1'674)' (Figtrre 3; an.1 u-.ing tlts nricr -.scope he Jls;.-.,.eied t}-re free living cells in pond rabbits, frogs, fish and insects' In 1678, 1-re Liis;or erecl sperr-n :.r : ii:r-.l:re ; ::'.e sp€rrn cells of humans, dogs, - -.: -,:..ei-Ler,1 rvallsof thecellsandnotthesubstancecontainedwithin Horr-er erlic..kel-raei or.-., s:= : discoveredandnamedthenucleus theser,r,a11s Ir, 1:li, a Scoitrsl^-:'-.'- i. RobertBrown (1773-1858) the term protoplasm in plant cells. J.E. I,urkinje i-S- - ,::. - -. -zec1-r animal physiologist, in 1839 gave ':-..i the nucleus was that the cei1. InL866, Haeckel established foithe living t-1ur; :*-.s;ar-i=---ir:= -.:.;itan' * -characters' responsible for stLr:-l- * -1' -r ir-' tl-- - - CellTheory.;ri:,-: lalotr\latt:.r->.h-leiden(1804-1881),aGermanbotanisffirstproposedtheideathatall plantsconsistoicells.,,r.=,::,,.:=: :-,r'-- TheodorSchwann(1810-1882),aGermanzoologis!independently thecelltheory' assertedthatallanima..:'r--- I ''-- : "' : r :-'= -r1's1 tt11s'Thisjointfindingformsthebasrsof 10 The Fundomentol Unit of Life: Cell I
