In the previous chapters, we have identified a range of ideational discourse semantic resources in the undergraduate biology texts and clarified both the congruent and metaphorical interstratal relations between the discourse semantics and lexicogrammar. This clarification enables us to identify discourse semantic patterns of sequence. In this chapter, we take a step from the stratum of discourse semantics towards the stratum of field, considering how the discourse semantic sequences construe dynamically the activities in the field.