reproduction is common to all organisms.This provides the ability to reproduce the succession and continuity of life.In organisms having cell structure shape based reproduction is division.
different scientists have been proposed various types of classification of reproduction.Generally considered three types of reproduction: vegetative, sexual and asexual.
In the latter case, the development of the body is made from a single cell, sexually undifferentiated.For vegetative reproduction characterized by the development of multicellular organism germs, sometimes difficult to differentiate.
Sexual reproduction of plants begins with the formation of sex cells (gametes).Needless reproduction is reduced to a merger of gametes into the zygote.This process is called fertilization and transmits genetic information from parents to offspring.
gametes are formed in the genitals - gametangia.Flora, which are characterized by fertilization, are in their life cycle meiosis.
Sexual reproduction is not typical for the blue-green algae, bacteria.Do not found a way of reproduction and a number of fungi.
Types of sexual reproduction in the lower species of flora are different.For example, some green algae reproduction process can take place without the formation of gametes.In this case, it merges the two single-celled organism.
fusion of gametes, which have flagella, called isogamy.Such sexual reproduction is typical of many algae.
unicellular algae (Chlamydomonas some, for example) to a certain degree turn themselves into sex organs forming gametes.In multicellular representatives gametangia are some that do not differ from other cells in any way gametangia with morphological differences (for example, ektokarpusa).
For many isogamous algae characteristic geterotallizm (genetic and physiological sexual division).Thus there is a merger of gametes physiologically different.
Some algae are characterized by the conjugation: there is "overflowing" protoplast of one cell to another.
fusion of gametes with different sizes flagella, called heterogamy.Connection bezzhgutikovoy female gametes (egg) and having flagella (mostly) small male (sperm) is oogamy.Such sexual reproduction is typical of a lot of red, brown, diatoms, green algae, and a number of lower fungi.
fertilization gologamnyh, heterogamic, isogamous and most oogamnyh flora is carried out in water.A number of plants oogamnyh merger process occurs in oogonia (female gametangia).They are actively moving sperm released into the water.The activity is apparently caused by chemotaxis.This spermatsii red algae (red algae) are moved by the water flow - passively.
Higher plants are oogamnymi.However, they fertilization occurs differently.For higher plants are typical multicellular gametangia - archegonia (female) and antheridia (male).The outer layer of cells of the genital organs are sterile.In archegonium one ovum formed in antheridia spermatozoa formed, usually in a large amount.
Sexual reproduction ferns and mosses carried out in water.Sperm out of antheridia and move to archegonia.In turn, ready to fertilize archegonia attract sperm penetrated the mucus from the summit.Moving in the mucus, the sperm closer to the egg, but merges with it alone.
