Spermatozoid(redirected from spermatozoids)
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(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.
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L. V. DANILOVA