1. Revenue bonds issued pursuant to the provisions of section 206.122 shall be of such denomination, shall bear such rate of interest not to exceed the highest rate permitted by law, and shall mature at such times as determined by the board of directors. The bonds may be either serial bonds or term bonds and may be issued with or without reservation of the right to call them for payment or redemption in advance of their maturity, upon the giving of notice and with or without the covenant requiring the payment of a premium in the event of the call and redemption prior to maturity as the board determines.

2. The bonds when issued and sold shall be negotiable instruments within the meaning of the law merchant and the negotiable instruments law and the interest thereon is exempt from income taxes under the laws of the state of Missouri.