From a group of four men and seven women, six are arranged in a row. How many different arrangements are there with each of the following properties?
1. The first three people in the row are men, and the second three are women.
2. Men and women alternate, with the first person in the row being a man.
3. Men and women alternate, with the first person in the row being a woman.
4. There are no restrictions; any of the positions could be a man or a woman.