useless trivia: What Word Means: An Egg-producing Organ?

Questions

What are siblings?

Which European country is a Grand Duchy?

What name is given to a blood vessel which takes blood away from the heart?

The National day of Ethiopia, 21st March, commemorates a victory at Adowa in 1896 over which country?

Which ultimately disgraced person was 'Surveyor of the Queen's Pictures' until 1972?