29456
This temporal sensing mechanism provides the bacterium with a memory of its passage through spatially - or temporally - varying signal fields , and adaptation is essential for successful chemotaxis .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None