How does the structure of flower fertilized by bees ensure its survival?

Oh, wow. People have written books on the subject. To try to be brief:
1. The flower offers nourishment in the form of pollen. In the course of
collecting pollen for food, the bee also deposits pollen on the next flower.
Some flowers, notably orchids, offer decorations that resemble pollen, or even
high-protein fake pollen, to attract bees.
2. The flower offers nectar, which the bees collect to make honey. In the act
of collecting nectar, they pollinate the flowers.
3. Bee pollinated flowers are usually fragrant. Colors are generally pink,
blue, yellow, or purple. Sometimes there are landing guides, perhaps visible
only in ultraviolet light.
4. Among the most highly evolved flowers, like orchids, there are certain
species where the flowers are modified into elaborate traps. When the bee lands
on the flower, she (in some bee species he) falls in the trap, & can't get out
without fertilizing the flower & picking up pollen for the next trip.
5. In a few really bizarre flowers, like Ophrys, the flower looks like a female
bee. A male bee tries to mate with it, & pollinates the flower in the process.

Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)