All three species of zebra have bold stripes in comparison to other African grazers like buffalo and antelope.
The life cycle of ferns is different from other land plants as both the gametophyte and the sporophyte phases are free living. This interactive illustrates the alternation of generations in ferns.ametophyte (prothallus). The prothallus is the fern gametophyte. It is a green, photosynthetic structure that is one cell thick, usually heart or kidney shaped, 3â10 mm long and 2â8 mm broad. It is very difficult to find in the bush as it is so tiny.
Most ferns reproduce by alternating generations between successive asexual and sexual forms. The sexual form, called the gametophyte or prothallium, is a tiny kidney-shaped haploid (N) plant that is difficult to find in the wild. The asexual form, or sporophyte form, is represented by the fern plant as it is commonly known and is diploid (2N). Sporophytes can reproduce either by vegetative cloning via their rhizomes or through spore formation via meiosis. Spores, rather than gametes, are the unicellular, haploid products of meiosis in fern plants. Spores in turn undergo mitotic cell divisions to produce the multicellular, haploid gametophyte. Relative to the familiar sporophytes, the fern gametophytes are small and inconspicuous. Commonly in primitive vascular plants, the haploid gametophyte phase occurs in a manner that allows it to be surrounded by tissues of the parent sporophyte, such as within cones, seeds, or pollen grains.