Topic: "Why in flowering plants called double fertilization 'studying in the sixth grade.However, not every adult can explain the intricacies of the process.
Plants, like all living things reproduce, using three main ways.The first is a vegetatively, that is, the new plant comes from a part of its "parent" - the root, stem, leaf, even a single cell.The second is called asexual, because the plants emerge from the debate and look at the motherboard.So multiply fungi and some algae.The most perfect is the fertilization of plants sexual way.
In the vegetable world, this process occurs through the fusion of gametes, which may be identical in size (isogamy), different sizes (heterogamy) and are fundamentally different from each other (oogamy).We can say that fertilization - a process connection male (sperm) and female (egg) gametes, resulting in the formation cell with a double set of chromosomes (zygote), from which the new plant will be.
Why flowering plants called double fertilization?Here there is a special organ of reproduction - a flower.Its components are on the stamen filaments with anther (the pollen contains), ovary, bar, pestle (with stigma), pollen tube that reaches the embryo sac where the ovule.Of course, many school biology remembers something about the pistil and stamen, and may think that's why the fertilization of flowering plants called double.But it is not.
in the anthers, as has been said, the pollen is formed, which consists of two cells - a large vegetative and smaller generative.When the boot is revealed, these elements are spread by wind or insects.Once on the pistil (directly on the stigma), pollen cells grow so that it becomes part of the vegetative pollen tube attached to the embryo sac.Through it in the bag gets generative cell, which in the course of their penetration is divided into two sperm.One of them reaches the egg it merges to form the zygote and the second is connected with the secondary core.This process is the reason why the fertilization of flowering plants called double.
Some modern plants successfully combine different methods of reproduction, which increases the survival of the species.And at a time when the process is just born, this way of reproduction was a very important evolutionary process.This is due to the fact that the body created by cell fusion with different sets of chromosomes, is highly variable and adaptable to the environment.Modern physico-chemical studies show how sexual reproduction of the plant complex in nature.For example, it was found that the pollen and stigma are of different pH, different levels of protein isoelectric points, different enzyme and amino acid composition, which, however, promotes the flow of physiological processes optimum for connecting these cells.
