Which branch can ratify treaties?
The President ratifies treaties after receiving the "advice and consent" of 2/3 of the Senate (not the full Congress).
It is a common misunderstanding that the Senate ratifies treaties.
The Legislative Branch has the power: of impeachment to override presidential vetoes to reject presidential appointments to reject treaties to withhold funding for initiatives The three branches are based on a separation of power controlled by a system of checks and balances. Congress can pass a bill vetoed by the President if they have a 2/3's majority and they appoint members of the Executive Branch. The Legislative Branch also ratify treaties, impeach, make laws, investigate…
The Senate has more than two powers, but a few of the powers they have that no other branch of the Federal Gov't has are: 1) To confirm Presidential appointments such as Supreme Court justices. 2) To ratify treaties made by the executive branch. 3) The Senate acts as judge and jury in impeachment cases.