test
node1
GO:0050896
response to stimulus
node2
GO:0042221
response to chemical
node1->node2
node4
GO:1901698
response to nitrogen
compound
node2->node4
node3
BFO:0000003
occurrent
node3->node3
node5
BFO:0000015
process
node3->node5
node6
GO:0008150
biological_process
node5->node6
node6->node1
node7
BFO:0000001
entity
node7->node3