Answer to Question 1
Figure 9.4 in the text is an example of the answer students should provide.
Answer to Question 2
Answers will vary. Figure GIA 15.2B nicely illustrates the process:
a narrow neck is formed when a lengthening meander loops back on itself; the necks narrows more due to undercutting, the stream erodes though the neck forming a cutoff; and, lastly, the oxbow lake forms as sediment fills the area between the stream channel and old meander.