They were brought to Europe from Turkey by the Crusaders.
No, tulips originated in the Middle East and Central Asia and were only brought to the Netherlands in the 16th Century.
forest
The English and Irish brought Halloween to America.
Netherlands
If you mean "Holland tulips", it means tulips from Holland.
There are no specific collective noun for tulips. I have seen suggested, an explosion of tulips and a tiptoe of tulips. However, any noun suitable for the situation can be used, for example, a field of tulips, a bouquet of tulips, a bunch of tulips, etc.
If you are saying that "1 in 4" of the tulips are red, the answer would be 4 of the tulips are red.
No, tulips are multicellular organisms.
Tulips are angiosperms.
Tulips
Tulips Tulips