2) Is there a birthday cake?
Yes, there is. There is one.
3) Is there one bottle of cola?
No, there is no. There are two bottles of cola.
4) Are there five glasses?
No, there are no. There are six.
5) Are there five lolipops?
Yes, there are. There are five.
6) Is there one present?
No, there is not. There are four.