(a)
A student performed an investigation into osmosis using Visking tubing. A sucrose solution, intended to model phloem sap at the source, was placed in Visking tubing tied at one end so that the tubing was about $75\%$ full. The remaining steps are shown in Fig. 2.1. After $20$ minutes, the tubing was taken out, dried and weighed again.
(a(i))[1]
Complete Fig. 2.1 so that it shows how the Visking tubing looks inside the test-tube after $20$ minutes.
(a(ii))[3]
State, with reasons, whether the mass of the Visking tubing holding the sucrose solution would alter after 20 minutes.
(b)[3]
Explain how osmosis takes part in the mass flow of phloem sap.
(c)[2]
The diagram shows two amino acids. Describe how a peptide bond forms between these two amino acids.