| MadSci Network: Botany |
Yes, most of the cell divisions result in the new cell wall being perpendicular to the cell column that the parent cell starts in. The first figure under the references shows the cell columns. The second figure in the references shows several cell divisions in columns. Cell divisions with the new cell wall parallel to the cell column do occur rarely as in the formation of lateral root primordium, which occur farther back from the tip (see last reference). A google.com image search on onion mitosis will locate more root longitudinal sections that show cells dividing. If you look at the root cap as in the third photo under references, not all the cells are arranged in columns. References Onion root tip longitudinal section Onion root tip longitudinal section Onion root cap Meristems Allium cepa Casimiro, I. et. al. 2001. Auxin Transport Promotes Arabidopsis Lateral Root Initiation. Plant Cell 13: 843�852.
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