It’s a Skarsgård takeover at Studio 8H. Alexander Skarsgård made his “Saturday Night Live” hosting debut this weekend on the 1,000th episode of the NBC series and was joined his father Stellan Skarsgård for two sketches. In the first , which mocked Stellan’s Oscar-nominated movie “Sentimental Value,” Alexander, 49, and Chloe Fineman play Swedish siblings grieving their ailing father, who turns out to be played by Stellan, 74. As the brother-sister duo go to the bathroom to say goodbye to their