Onions don't need chlorophlast because they grow underground. Chlorophlast is used in the process of photosynthasis which needs the sun. That is why Onions don't ahve chlorophlast.
The general shape of the epithelial cells that are nearest
to the lumen in an empty urinary bladder is in multiple cell layers which are
considered to be a stratified tissue and the cells in it are shaped in terms of
the organ’s distention. This type of epithelial cell is the transitional
epithelium.
