Not all flowers require insects for pollination.
Most angiosperms (flowering plants), in particular dicotyledonous plants, require an agent of pollination; normally these are animals - mainly insects, but can also be birds, mamals, centipedes etc.
Monocotyledonous angiosperms which comprose largely of grasses are pollinated mainly by wind.
Gymnosperms (cone bearing plants) rely mainly on wind pollination and therefore produce large quanitites of pollen.
In short, they do. Greenhouses are not usually sealed, and insects can get in and out, and they will pollinate the flowers.
Because these colours attract insects and the flowers need the insects to pollinate them. Hope this helps!
yes flowers need particular insects to pollinate them.
yes
yes because they do not need to attract insects to pollinate them
To attract insects to pollinate the plants.
There will be no flowers and fruits.
Flowers attract insects. Insects pollinate the flowers. Pollinated flowers produce seeds. Seeds grow into apples.
No. There are plenty of other insects which pollinate flowers.
Flowers smell to attract the insects that pollinate them.
You let the insects pollinate the flowers, then you grab the flowers and feed the plant to the animal.
Flowers attract insects. Insects pollinate the flowers. Pollinated flowers produce seeds. Seeds grow into apples.