Ihab El-Islamboly, an English teacher in Alexandria, was questioned by police on Tuesday for setting a "politicised" exam question that "insulted" President Mohamed Morsi.
The question that angered some members of the Alexandria teachers' syndicate, which El-Islamboly says is dominated by the Muslim Brotherhood, included the quote, "In the animal kingdom, a sheep cannot be king."
El-Islamboly told Al-Ahram Arabic news website that he had not intended to insult the president, who hails from the Brotherhood, and the quote is part of the curriculum.
"What part of this quote has anything to do with the president or politics?" asked El-Islamboly.
Critics often accuse Muslim Brotherhood members of acting like sheep for slavishly following the orders of the group's supreme-guide.
On Saturday, the deputy education minister in Kafr El-Sheikh governorate ordered the punishment of an English teacher for including a question involving an imaginary dialogue between ousted president Hosni Mubarak and his successor Morsi.
Early last year, a teacher in the Nile Delta governorate of Sharqiya was penalised for setting an exam that included a question equating protesters with criminals and another requesting an essay congratulating the Muslim Brotherhood's Freedom and Justice Party for winning a majority in Egypt's first post-Mubarak parliamentary polls.