The Knesset is divided into committees, which amend bills on various appropriate subjects. Committee chairpersons are chosen by their members, on recommendation of the House Committee, and their factional composition represents that of the Knesset itself. Committees may elect sub-committees and delegate powers to them, or establish joint committees for issues concerning more than one committee. To further their deliberations, they invite government ministers, senior officials, and experts in the matter being discussed. Committees may request explanations and information from any relevant ministers in any matter within their competence, and the ministers or persons appointed by them must provide the explanation or information requested.