El polen de las plantas se utiliza para transferir material genético masculino haploide de la antera de una sola flor al estigma de otra en la polinización cruzada. En un caso de autopolinización, este proceso tiene lugar desde la antera de una flor hasta el estigma de la misma flor.
Symbioses are close interactions between species that have evolved over long periods of time. When these interactions enhance the reproduction and population growth of both species, they are called mutualisms.
In mutualism the relationship benefits the two organisms, the relationship can be within the species, between living things fro two different species among others. Example is the digestive bacteria and humans; Some food cannot be digested, therefore when these foods are consumed, the bacteria in the digestive tract feed on these foods, therefore the bacteria stays alive and humans gets helps in digestion.