Question 3(c)(iii)
[Maximum number: 2]
Fig. 3.1 shows a photomicrograph of a section of a root.
Fig. 3.1
Scientists wanted to determine the flow-rate of water in roots.
They measured the flow-rate in three zones of onion roots as shown in Fig. 3.2.
Fig. 3.2
They measured the flow-rate in healthy roots and roots that had been treated with a toxic solution.
Their results are shown in Table 3.1.
Table 3.1
Suggest why there was little difference in the flow-rate in healthy roots and in roots treated with the toxic solution.