Reproduction by spores in plants occurs only via a single cell called a spore. Spores usually arise in special organs - sporangia. Spores are either

Plant propagation by spores [reproduction]

Reproduction by spores in plants occurs only via a single cell called a spore. Spores usually arise in special organs — sporangia.

Spores are either fixed or have mobility. The first are distributed passively after rejection from the sporangium by wind or water current. Mobile spores have flagella (cilia) in the form of thin plasma filaments, extending from the forward end of the cell by its large part, and are called zoospores. Accordingly, sporangium in which they form is called zoosporangia.

In most cases the mobile zoospores have bare protoplast, deprived of shell. The latter forms only after zoospore goes to a sedentary lifestyle, ceasing its movement, and having attached to the substrate. Taken from http://worldofschool.org

Spores differ in the details of its origin methods. You can distinguish the spores that always arise as a result of re-division of the mother cell, through the so-called quadrupling. The latter means that from one mother cell, necessarily form four cells, otherwise known as tetrads. Characteristically, that the first division of the parent cell's nucleus is always meiosis, i.e., reducing the amount of nuclear material in half, and that this meiosis occurs only once in the development cycle of each individual — before the formation of the tetrad of spores.

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