cell and cell organelle Cell and cell theory cell and cell diagram .

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Study of Animal Cell

Study of animal cell and its organelles with the help of charts /slides.


EXPERIMENT NO. 4


AIM: To study cell and cell organelles by charts/slides.


CELL AND CELL ORGANELLES


CELL  AND CELL THEORY. 


Cell: "A cell is the smallest but complete expression of the fundamental organization and functions of all living organisms. It is a mass of nucleated cytoplasm delimited by a semipermeable cell membrane and is capable of reproducing in a medium free of other living systems.


History of cell:

History : The study of cell started with the discovery of micros cope (Janssen 1590). The term cell was introduced by Robert Hooke (1665), who observed hollow cavities or spaces in thin slices of cord under a crude micros cope. With the improved magnification, the detailed structure of cell was studied and the electron microscope has revealed the minute details of cells organelle.


Shape: The cell be spherical, oval, rounded, elongated, cuboidal, cylindrical, tubular, polygonal, plate-like, discoidal or irregular.







Size: Cells are usually microscopic, visible only under high power of microscope, but some may be submicroscopic, while others macroscopic. The smallest cells are those of pleuropneumonia virus.

Mycoplasma gallisepticum, which measures about 0.1 u (= .001 mm). Leucocytes are 3-4 u but the muscle
cells and nerve cells are long. A nerve cell in human body measures about 3 ft. An ostrich egg is about 175
mm and hen's egg 50 mm.

Structure: A generalized cell is differentiated into (i) plasma membrane or cell membrane,

(ii) cytoplasm and (iii) nucleus.


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