How does self-pollination differ from cross-pollination?

Self-pollination occurs within the same flower or plant, while cross-pollination involves the transfer of pollen between different plants.

Self-pollination and cross-pollination are two distinct methods of pollination in plants. Self-pollination, as the name suggests, is a process where the pollen from the anther (male part) of a flower is transferred to the stigma (female part) of the same flower or a different flower on the same plant. This method of pollination does not require an external agent, such as wind or insects, for the transfer of pollen. It ensures that the plant can reproduce even in the absence of such agents or other flowers. However, it also limits the genetic diversity of the offspring as the genes come from the same plant.

On the other hand, cross-pollination involves the transfer of pollen from the anther of a flower on one plant to the stigma of a flower on a different plant. This process usually requires an external agent, such as wind, water, or animals, to facilitate the transfer of pollen. Cross-pollination promotes genetic diversity as it combines genes from two different plants. This genetic diversity can lead to offspring with new traits that may be beneficial for survival, such as resistance to diseases or adaptation to different environments.

In terms of evolutionary advantage, cross-pollination is generally more beneficial as it leads to greater genetic variation and hence, a higher chance of survival in changing environments. However, self-pollination can be advantageous in stable environments or situations where cross-pollination is less likely due to the absence of pollinators or other plants of the same species.

In summary, self-pollination and cross-pollination are two different methods of pollination that occur in plants. While self-pollination occurs within the same flower or plant and does not require an external agent, cross-pollination involves the transfer of pollen between different plants and usually requires an external agent. Both methods have their own advantages and disadvantages, and the choice between them depends on the specific circumstances and environment.