It is constantly replaced by newly formed cells as the older tissue is sloughed off with growth of the root through the soil.

 
  • 隨著(zhù)根尖的生長(cháng),根冠外層的薄壁細胞與土壤顆粒磨擦,不斷脫落,死亡,由其內的分生組織細胞不斷分裂,補充到根冠,使根冠保持一定的厚度。
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