Cut tulips continue to grow because of phototropism. When cut and placed in a vase, the tulips bend towards the light, and so they elongate.
Tulips Lillies
You cut a tulip at the very end of the stem at a 45 degree angle. You can cut the stem as short as you want to put in a certain size vase after you have cut it properly from the ground.
Cutting and wrapping tulips is a very delicate process. The following website offers some tips and tricks to help your tulips last longer, http://gardening.about.com/od/craftsanddecor/qt/TulipCare.htm
After you cut a tulip flower off of the plant, the leaves start to send nutrients back to the bulb to store for next year's flower. If you cut the leaves off along with the flower, your tulips will continually grow smaller each year. If you leave the stem and let it go to seed, they will also grow smaller next year.
The root word for section, sectio, is derrived from the Latin word secare (meaning to cut).
tulips (two lips...)
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