Your friend told you an anecdote, possibly in jest, because the truth seems comically twisted beyond recognition. Historical events dating back to 1930-1960s did influence the development of Soviet science in ways more favorable to physics than to biology. Much has changed since then, including cultural attitudes and government funding, but those events did leave a lasting mark on the tradition.
For ideological reasons Stalin opposed genetics and cybernetics as "foreign influences", and promoted agricultural pseudoscience of the likes of Trofim Lysenko, who promised results in the spirit of "transforming the world", the official Soviet ideology at the time. According to Sakharov, "he is responsible for the shameful backwardness of Soviet biology and of genetics in particular, for the dissemination of pseudo-scientific views, for adventurism, for the degradation of learning, and for the defamation, firing, arrest, even death, of many genuine scientists." The poisoned atmosphere in Soviet biology during the late Stalin years is portrayed in a celebrated 1987 novel White Garments by Vladimir Dudintsev, which is translated into English. Unfortunately, Lysenko managed to engratiate himself to Khrushchev as well, so he remained a smothering influence in biology until Khrushchev's removal in 1964.
Physics and mathematics, on the other hand, enjoyed a somewhat greater degree of research freedom because Stalin was interested in potential military applications, the nuclear bomb in particular, more than in the ideological purity of physicists and mathematicians. This attracted many bright and independent people to these fields. In 1960s nuclear physics enjoyed broad popularity, physics degree programs at universities even became some of the most competitive ones for a while. Unlike high minded intellectual debates about Snow's "two cultures" the Soviet version of the controversy, nicknamed "physicists and lyricists", became a truly popular culture phenomenon. Interestingly enough, it was public denunciation in 1962 of Lysenko's work as pseudoscience, and of his use of political repression to silence and eliminate opponents, by three prominent Soviet physicists, Zel'dovich, Ginzburg and Kapitsa, that hastened his demise.