Re: What is the largest animal cell and the largest plant cell?

Dear Heather,
   The answer to your question about animal cells is not actually quite as 
simple as it might seem.  If you're referring to a cell with a single 
nucleus, probably the largest one is an egg cell in the ovary, which can 
measure as much as 1/10 of a mm in diameter.  However, specialized cells in 
the body can arise via the fusion of many cells into a huge cell with many 
nuclei.  For example, a muscle fiber is actually one very long and wide 
cell with many nuclei--perhaps 1/10 of a mm wide and several centimeters 
long.  Also, the outermost layer of the placenta is made of one undivided 
sheet of cytoplasm containing thousands of cell nuclei--the 
syncytiotrophoblast--that covers the entire surface of the membranes 
enclosing a developing baby.  So living tissue enclosed within a single 
cell membrane can be extremely large in animals.  To my knowledge, plant 
cells do not show such great variability in size and are all less than 1/50 
 of a mm in diameter.  You can find out more about cells in a book I wrote 
that may be in your school library.  It is called Cells: Amazing forms and 
functions by John Young, 1990.