Q. Do protozoans have asexual or sexual reproduction?
In protozoans reproduction is asexual or sexual. The most frequent form of sexual reproduction is binary scissiparity or division in which the cell divides it by mitosis originating two daughter cells. Some species like the plasmodium agent of malaria reproduce asexually by schizogony multiple fission, in this form of the reproduction 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 definitive host, the mosquito, and the zygote undergoes mitosis (sporogony) creating many sporozoites.