Protist+Reproduction

= Protista reproduction = = (Amoeba) Amoebas are an example of a single-celled protist that reproduce asexually, which simply means a single parent produces an offspring without fertilization by another. First, the amoeba creates an exact replica of its nucleus, which is called mitosis. Then, in a process called fission, the amoeba splits itself into two cells with one nucleus in each. As a result, the pair is genetically identical. Fission is the predominant method of asexual reproduction in single-celled protists, though some fungus-like protists produce spores, another method of asexual reproduction. = =Another method of reproduction that has aspects of both sexual and asexual reproduction is the process by which bacteria exchange genetic information, called conjugation. After joining with another bacterium through a special straw-like tube, a single DNA strand from a donor is injected into a recipient. The process is not properly sexual, however, because there are no haploid gametes formed. = =Most of the protists reproduce by mitosis, and some by meiosis and reproduction. =

(Protozoan)In protozoans reproduction is sexual or asexual. The most frequent form of sexual reproduction is binary division, or scissiparity, in which the cell divides itself by mitosis originating two daughter cells. Some species, like the plasmodium, agent of malaria, reproduce asexually by schizogony (multiple fission); in this form of reproduction the cell becomes multinucleated, generally inside  a host cell, and each nucleus is expelled out together with cytoplasm portions giving rise to new protozoans. The sexual reproduction in protozoans can happen by conjugation, with incorporation of genetic material from one cell into another, or by gametes that fecundate others and form zygotes. In the plasmodium sexual reproduction happens in  the mosquito, the definitive host, and the zygote undergoes mitosis (sporogony) creating many sporozoites.