stigma
When bees land on flowers, their fuzzy legs pick up pollen. When they do, they fly to other flowers. While they're sucking up nectar, their legs rub off pollen. That pollen helps the flowers grow.
Many plants coevolve with a pollinator. Bumblebees and the flowers they pollinate have coevolved so that both have become dependent on each other for survival. Some flowers have coevolved with hummingbirds that pick up pollen when they fly inside the blossom to get nectar.
Butterflies with hairy legs pick up more pollen. This adaptation would help a butterfly pollinate more flowers by carrying more pollen.
The tiny yellow grains that bees collect from flowers are called pollen. Pollen is a fine powder produced by the male parts of flowers and serves as a vital source of protein and nutrients for bees. When bees visit flowers, they transfer pollen from one bloom to another, facilitating the process of pollination, which is essential for plant reproduction.
This is part of the process of pollination. The animal may be referred to as a pollinator or a vector.
So that pollinators with long mouth-parts can collect nectar from the flower and also pick up pollen.
to pick up pollen
Pollination
Bees can see ultra-violet light, and there are patterns on the petals of many plants which are visible only in ultra-violet and lead the bee to the source of nectar. The flowers are so arranged that as the bee goes to the nectar it will brush against the stamens and pick up pollen.
Pollinators are attracted to the nectar. When they are feeding on the nectar, they pick up pollen and/or deposit pollen. The location of the nectaries is such as to make the pollinators touch the pollen to pick it up or to deposit it.
Honeybees eat nectar and pollen, which they gather from flowers. They use their long proboscis to suck up nectar from flowers and collect pollen in specialized baskets on their hind legs called pollen sacs.
They are artificially pollinating the flowers. If a bee come along then the hairs on it's legs will pick up pollen and then move on to the next flower and some of the pollen will fall of and into the flower. The gardener is trying to act like a bee and pollinate his tomatoes so he gets more tomatoes from every plant.