America reviewed state line and biological category (8)
I believe the answer is:
suborder
'biological category' is the definition.
'suborder' can be an answer for 'category' (I have seen 'Taxonomic category ' mean 'suborder' so perhaps 'category' could also mean 'suborder'). I'm unsure of the 'biological' bit.
'america reviewed state line' is the wordplay.
'america' becomes 'US' (United States).
'reviewed' is a reversal indicator.
'state line' becomes 'border' (border is a kind of line. I am not sure about the 'state' bit.).
'us' in reverse letter order is 'su'.
'su'+'border'='SUBORDER'
'and' is the link.
Can you help me to learn more?
(Other definitions for suborder that I've seen before include "Group of creatures" , "A number of families" , "Taxonomic category above family" , "Group of animals" , "Botanical group" .)