The personnel that form the executive (government) are drawn from the personnel who are appointed or elected to the legislature.
The personnel that form the executive (government) are appointed or nominated by the head of the executive, the President.
The state has one source of legal power, held centrally.
The state has more than one source of power, held independently by the local/regional/state governments and central governments.
Introduction or proportional representation; replacement of the House of Lords with an elected Senate; power to establish Parliaments in Scotland, Wales and Northern Ireland and assemblies in the English regions; the incorporation of the European Convention on Human Rights as a Bill or rights; the creation of a Supreme Court.
The UK would become a Commonwealth; the Monarchy would be replaced by a President elected by 2/3 majority of the Commonwealth Parliament; Royal prerogative powers would be transferred to the President; certain rights would be entrenched but only enforceable by a Human Rights Commissioner and judicial review; the House of Lords would be replaced by the elected House of the People, the PM was to be elected by the Commons; national Parliaments for England, Scotland and Wales and the jurisdiction of Britain in Northern Ireland would cease.
Retention of the Monarchy, but with reduced power; Bill of Rights combing the European Convention on Human Rights and the ICCPR; Parliament for the UK but assemblies for Scotland, Wales and Northern Ireland and the English regions; PM to be elected by the Commons; ministerial responsibility to become a constitutional duty; the electoral system to be changed to allow for Additional Members system in the Commons and a Single Transferable Vote in the Upper Chamber; Minster of Justice and a Supreme Court; constitutional provisions may be entrenched if the House of Parliament agree with a majority of at least 2/3 voting, made up of at least ½ of the members..