If the stigma is messed up it is hard for bees or insects to pollinate because the way they pollinate is by eating the nectar from the stigma and stick the pollen on their body and stick it on the stigma.
But if there is no stigma=no pollination
A good example of a model is a lily
The best answer is the isotope of strontium which is strontium-85. It has a half-life of about 64 days. The metal strontioum has four stable, naturally occurring isotopes which includes 84Sr (0.56%), 86Sr (9.86%), 87Sr (7.0%) and 88Sr (82.58%).
B. When electrons gain energy, they have the power to move up to a higher energy level in an atom.