  In this paper we consider reduced homogeneous ideals $\Jcal\subset S$ of a
polynomial ring $S$, having a 2-linear resolution.
  1. We study systems of generators of $\Jcal\subset S$.
  2. We compute the arithmetical rank for a large class of projective curves
having a 2-linear resolution.
  3. We show that the fiber cone $\proj \Fcal(I_{\Lcal})$ of a lattice ideal
$I_{\Lcal}$ of codimension two is a set theoretical complete intersection.
