Spermatozoid

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Spermatozoid

 

(also antherozoid), a male sexual cell of many plants. Spermatozoids with two or more flagella are found in green and brown algae and in some lower fungi, mosses, ferns, horsetails, club mosses, quillworts, selaginellas, Cycadopsida, and ginkgos.

Spermatozoids lack a cellulosic coat and are usually very small, with the exception of those in some Cycadopsida that reach 300 micrometers in diameter and are visible to the naked eye. In spite of their small size, they usually have a large nucleus and a small quantity of cytoplasm. The flagellum is situated at the anterior end of the spermatozoid, in the direction of movement. Movement toward ova is made possible by various chemical substances constituting the female sexual cells and organs.

Most spermatophytes are characterized by the presence of sperm, nonmotile male sexual cells that lack flagella, since fertilization in plants does not depend on a liquid medium.

REFERENCES

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L. V. DANILOVA

References in periodicals archive ?
Spermatozoids were extracted from the vas deferens sections by pinching one end with splinter forceps and using another splinter forceps, from which the serrations had been completely eliminated leaving a smooth surface, to squeeze the duct fragment and extract the spermatozoids.
multiflagellated spermatozoids, one of which fertilizes a waiting egg
This species fertilizes its eggs by ingesting the spermatozoids released into the environment, but unlike most anemones, it does not release the eggs or the larvae, but instead incubates them until they are small adults, which immediately settle on the substrate on expulsion into their surroundings.
A quick sketch, circa 1949, shows a pile of lines more or less evocative of spermatozoids to which two tires are added toward the bottom; "Will Jackson Pollock affect our cars?
Chemical interaction in sexual reproduction of several Laminariales (Phaeophyceae): release and attraction of spermatozoids.
Nevertheless, these techniques are widely used in many laboratories to study the chromosomes of human spermatozoids, in fertilizing hamster eggs to determine the quality of semen from donors for artificial insemination.
Carotenoids constitute one of the most important pigments in fish, and have a wide variety of functions including protection against adverse illumination, acting as a ProVitamin A, improving immune response, reproduction, growth, and maturity, regulation of chemotaxis in spermatozoids and is also a powerful antioxidants (5).
For male acini, germinal cells sat within the inner wall of the acinus, with spermatocysts, spermatids, and spermatozoids developing toward the lumen.
In this study, the presence of spermatozoids in all months of the year was observed in most of male gonads and concerning the immature individuals, these were not observed in either female or male.