Life Sciences Paper 1, November 2024, question 3.5.1(a)

A learner wanted to find out how a plant hormone affects the way shoots grow. She used nine seedlings of the same species, split into three sets of three: set P, set Q and set R. All seedlings were grown in a dark cupboard for two days at the same temperature and given the same amount of water. - Set P: the shoots were left untouched. - Set Q: the tip of each shoot was removed and a small block of jelly (agar) containing the hormone was placed on the cut surface. - Set R: the tip of each shoot was removed and a block of plain agar with no hormone was placed on the cut surface. After two days she compared how the shoots had grown.