title: UML one-to-one diagram
body: <p>I would like to ask you which of these UML diagram is best according to "best practices".
  One is given by my teacher and the other is mine, but the main difference I have doubts is the one-to-one vs. attribute with no one-to-one relationship. Please, could you tell me why should be one better than the other?</p>
  
  <p><img src="https://i.stack.imgur.com/Py9Sf.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/D5847.jpg" alt="enter image description here"></p>
  
  <p>The problem also said: "The ConsejoDepartamento has to have one director that is a Miembro, but must be a Profesor. So does the secretario too"</p>
  
  <p>(Please, excuse my bad English!)</p>
  
  <p>Thank you very much!</p>