Добавить HTML, кроме определенного класса, с помощью jquery

$("input:checkbox").click(function(){
  if (this.checked) {
    $("ul#assetSelectedList").append($("ul#mosaic").html());
    $('ul#assetSelectedList input:checkbox').prop('checked', this.checked);
  }
  else {}
});

<script src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type = "checkbox" name = "thing" value = "valuable" id = "thing1">
<ul id = "mosaic" class = "clearfix list">
  <li class = "clearfix asset-free-li">Asset Free</li>
  <li class = "clearfix asset-free-li">Asset Free</li>
  <li class = "clearfix asset-paid-li">ASSET PAID</li>
  <li class = "clearfix asset-free-li">Asset Free</li>
  <li class = "clearfix asset-free-li">Asset Free</li>
  <li class = "clearfix asset-paid-li">ASSET PAID</li>
  <li class = "clearfix asset-free-li">Asset Free</li>
  <li class = "clearfix asset-free-li">Asset Free</li>
</ul>
<ul id = "assetSelectedList" class = "clearfix list"></ul>