Combining conditions in an IF condition

Can't we have this in a single SQL without using IF

IF (@PPRODUCT_TYPE_ID != '0')   
    SELECT * FROM PRODUCT 
    WHERE 
        PRODNAME = @pName 
    AND 
        PRODUCT_TYPE_ID IN (SELECT DISTINCT ID FROM PPRODUCT_TYPE)
ELSE
    SELECT * FROM PRODUCT 
    WHERE PRODNAME = @pName