Why cross pollination is advantageous

This method of pollination does not require an investment from the plant to provide nectar and pollen as food for pollinators. Living species are designed to ensure survival of their progeny; those that fail become extinct. Genetic diversity is therefore required so that in changing environmental or stress conditions, some of the progeny can survive.

Self-pollination leads to the production of plants with less genetic diversity, since genetic material from the same plant is used to form gametes, and eventually, the zygote. In contrast, cross-pollination—or out-crossing—leads to greater genetic diversity because the microgametophyte and megagametophyte are derived from different plants.

Because cross-pollination allows for more genetic diversity, plants have developed many ways to avoid self-pollination. In some species, the pollen and the ovary mature at different times. These flowers make self-pollination nearly impossible.

By the time pollen matures and has been shed, the stigma of this flower is mature and can only be pollinated by pollen from another flower. Some flowers have developed physical features that prevent self-pollination. The primrose is one such flower.

Insects easily cross-pollinate while seeking the nectar at the bottom of the pollen tube. This phenomenon is also known as heterostyly.

Many plants, such as cucumber, have male and female flowers located on different parts of the plant, thus making self-pollination difficult. In yet other species, the male and female flowers are borne on different plants dioecious. All of these are barriers to self-pollination; therefore, the plants depend on pollinators to transfer pollen. The majority of pollinators are biotic agents such as insects like bees, flies, and butterflies , bats, birds, and other animals.

Other plant species are pollinated by abiotic agents, such as wind and water. Examples of self-pollinating plants include wheat, barley, oats, rice, tomatoes, potatoes , apricots and peaches. Many plants that are capable of self-pollinating can also be cross pollinated. Cross pollination is advantageous because it allows for diversity in the species, as the genetic information of different plants are combined.

However, it relies on the existence of pollinators that will travel from plant to plant. Self pollination leads to more uniform progeny, meaning that the species is, for example, less resistant as a whole to disease.

However, it does not need to expend energy on attracting pollinators and can spread beyond areas where suitable pollinators can be found. Share this comparison:. If you read this far, you should follow us:. Diffen LLC, n. Cross Pollination vs. Self Pollination. Comparison chart Cross Pollination versus Self Pollination comparison chart Cross Pollination Self Pollination Definition Cross pollination is the transfer of pollen grains from the anther of a flower to the stigma of a flower of a different plant of the same species.

Some legumes, e. Orchids, peas and sunflowers, wheat, barley, oats, rice, tomatoes, potatoes, apricots and peaches. Transfer Wind, insects, water, animals, etc.

Shed pollen directly onto stigma. Plant differences Brightly colored petals, nector and scent, long stamens and pistils. Smaller flowers. Results More variety in species. It allows for diversity in the species, as the genetic information of different plants are combined. More uniform progeny.