One of the poisonous substances that plants secrete is oxalic acid. Plants convert it into insoluble and therefore safe calcium oxalate. It is deposited as crystals of various shapes in old dying cells. Work in the field and propose hypotheses of what are the advantages and disadvantages of alienating toxic substances into dead cells instead of being expelled outside.
Benefits: strengthening the plant; protection against eating by animals; Disadvantages: if the acid got into the environment (soil), the plants would be inhibited, because most of them do not like acidic soils.
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