The two types of pollination, self and cross, are compared. This article includes advantages and disadvantages and a definition of each type.
Before we compare the types of pollination we need to know how to define it.
Simply saying, pollination is the transfer of pollen from the anther to the stigma of a flower. This is just a simple definition but pollination involves many other things. We can divide pollination into two types. Cross Pollination and Self Pollination.
Now lets compare.
This type of pollination occurs when the anther and stigma are either in the same flower, or in different flowers on the same plant. As the offspring produced are genetically identical to the parent we can also call it asexual reproduction. To see asexual and sexual reproduction compared in another article click here (will open in a new window).
Obviously the genes in one same flower are the same. So this will obviously have to be called self pollination. Something most people mix up is when pollination occurs between different flowers of the same plant. This is also self pollination as the same set of plant genes are involved.
So in self pollination either only one flower is involved or the two flowers involved are from the same plant.
Self pollination can make sure that a species of plants would not go into extinction as two different plants are not needed to reproduce. If two different plants of the same species are required then there is less chance of pollination happening that often. In other words less offspring produced in cross pollination so there is a higher chance of extinction but plants using self pollination have nothing to fear. They can produce offspring on their own using one parent.
The offspring produced are genetically identical to the parent so that means if the parent plant can survive in a certain habitat then the offspring will also surely be able to survive in the same habitat.
As offspring are genetically identical there is no variation so therefore no evolution. Disease may also easily spread among identical offspring.
Electron micrograph showing pollen grains.
Image via Wikipedia
Cross pollination is entirely different from self pollination. An important thing to remember is that in Cross Pollination there are always two plants involved. As the offspring are not genetically identical to the parent plant this can be called a form of sexual reproduction. To see asexual and sexual reproduction compared in another article click here (will open in a new window).
Cross pollination occurs when the two flowers involved are from different plants rather then from the same one. Two flowers from different plants mean that different set of genes are involved. It also very important to remember that the two different flowers involved must be of the same species.
So you can also define it in another way. Cross Pollination occurs when the anther and the stigma are in flowers on different plants of the same species.
Since offspring are not genetically identical to the parent there are variations and these can lead to evolution. Diseases wont affect all offspring at once as non of them are genetically identical.
Not a very sure method as the pollen might not reach the stigma. Two parent flowers from two different plants from the same species are required.
Cross and self pollination have their own methods, advantages, disadvantages and features. Most of them were simply summarised above.
This is all for now about pollination. If you have any questions or suggestions please comment below. If you found this article helpful please support me (Nivu Whatani) by reading my other articles.