Life and career
Keynan was born by the name Alexander Kotznok in 1921 in Kiev, Ukraine to Rachel and Ephraim Kotznok (1883–1963) whom was an industrialist, insurance man and an active Zionist. In 1930, Keynan immigrated with his family to Israel. Keynan studied for a M.Sc and Ph.D. at the Hebrew University (he graduated in 1950 with his work on "The biological and biochemical studies of Clostridium botulinum") while serving the scientific department of the Jewish paramilitary organization Haganah. In 1948, with the establishment of the IDF, Keynan joined the Science Corps (חיל המדע) and soon thereafter was a founding member of the Israel Institute for Biological Research in Ness Ziona and its first director. Keynan served as the Chief Scientific Director of the Institute and the director of the Institute of bacteriology.
In 1964, Keynan was appointed to the chairman position of the National Council Civilian Research and Development (Hebrew: המועצה הלאומית למחקר ופיתוח אזרחי). In 1967 Keynan was appointed as the head of the Institute of Life Sciences (המכון למדעי החיים) at the Hebrew University. During this period he was appointed as a member of the Atomic Energy Commission (הוועדה לאנרגיה אטומית).
In 1945, Keynan married the Malka Ben-Zvi. The couple had two daughters.
His aunt (the sister of his father) was the publisher Bracha Peli.