The entrepreneur doesn't have a boss, but they are responsible to others. I just finished 5 parts on "The Customer" as the entrepreneur's Boss: (1,2,3,4,5). The entrepreneur is also beholden to their employees. Good executives know the importance of surrounding themselves with smart, talented and dedicated people. They also know that great people deserve and expect great treatment.
Startups are by their nature risky environments. An executive has the responsibility of providing as much stability and longevity as possible given the risky nature of the business. Identifying and avoiding unnecessary risks is essential. Given the relative inexperience of most entrepreneurs, this means surrounding oneself with knowledgeable advisers. Gathering data about your industry and identifying trends are essential. This advice allows an entrepreneur to intentionally balance growth and risk instead of being blindsided by emergencies.
Doing right by employees starts at the hiring process. Entrepreneurs at startups have a duty to be clear about startup culture and potential risks to the business. Within reason, be up front about financial outlook and possible major finance changes. Be frank about long hours and intense activity. Acting with integrity means ensuring that each candidate has eyes wide open when accepting their position.