The solicitor would have asked you this as you could have bought either as 'tenants in common' or as 'joint tenants'. If as joint tenants, your partner would automatically inherit your share. If as tenants in common, your share would go by way of your estate, and if no will made would go to your next of kin ( parents or brothers sisters depending on who survives you). It sounds like your solicitor covered this for you but no harm to check. Do you have a copy of your title? If not, you could ask the solicitor.
By the way, it is not readily apparent on the title- if you are registered as joint tenants it will simply have your names down as registered owners and will be silent otherwise. If as tenants in common- it will say ' Mark Owens and Sharon O' Keefe as tenants in common with an undivided one half share each' or something similar.