Shout about unicellular organism in Canadian city (7)
I believe the answer is:
calgary
'canadian city' is the definition.
(I've seen this before)
'shout about unicellular organism' is the wordplay.
'shout' becomes 'cry' (synonyms).
'about' indicates putting letters inside.
'unicellular organism' becomes 'alga' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'cry' enclosing 'alga' is 'CALGARY'.
'in' is the link.
Can you help me to learn more?
(Other definitions for calgary that I've seen before include "Canadian city" , "City in southern Alberta" .)