Sentence:  Thus , the alignment of the `` dots '' and `` tips '' , respectively , indicate individual variability of the 21 <WSD>growth</WSD> centers of each child with respect to the mean values for these boys and girls . 
Meaning of the word marked with <WSD> tags:  (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level