Re: What is cell elongation?

Cell elongation is one of a number of ways in which cells can become 
specialized to perform a certain function.  All multicellular organisms 
begin as a single cell--a fertilized egg.  This cell and its daughters 
undergo several rounds of cell division, which produces a big clump of cells 
that all look alike.  However, if you examine a multicellular organism, such 
as yourself, you'll notice that you are much more than a big clump of 
homogenous cells (I assume).  So how did you go from being a clump of cells 
to a person with lots of different cell types (like bone cells, muscle 
cells, nerve cells, etc.)?  Through a process called DIFFERENTIATION.  
Fairly early in embryonic development, genetic signals cause one cell or 
group of cells to become different from their neighbors.  This change 
results in the cells behaving and looking different than their neighbors,  
and ultimately these different cells will be able to perform special 
functions unique to that cell type, such as building bone, or transmitting a 
neural impulse.  

Now, to directly address your question:  Differentiation often results in a 
cell changing its shape so that it can better perform the function it is 
being specialized for.  One way for a spherical cell to change shape is to 
elongate.  Elongated cells often like to crowd together (picture a row of 
bottles or test tubes laid out side by side), and many tissue layers in the 
body are made of these tightly packed, elongated cells.  

Thanks for your question, I hope this information is what you were looking 
for!  Please write back if you need further help with this topic.
 
Warm Regards,
Jen