Weegy: In those algae which have alternation of generations, the sporophyte and gametophyte are separate independent organisms, which may or may not have a similar appearance. [ In liverworts, mosses and hornworts, the sporophyte is less well developed than the gametophyte, being entirely dependent on it in the first two groups. By contrast, the fern gametophyte is less well developed than the sporophyte, forming a small flattened thallus. In flowering plants, the reduction of the gametophyte is even more extreme; it consists of just a few cells which grow entirely inside the sporophyte.
All animals develop differently. A mature animal is diploid and so is, in one sense, equivalent to a sporophyte. However, an animal directly produces haploid gametes by meiosis. No haploid spores capable of dividing are produced, so neither is a haploid gametophyte. There is no alternation between diploid and haploid forms.
Other organisms, such as fungi, can have life cycles in which different kinds of organism alternate. The term 'alternation of generations' has also been applied to these cases.[citation needed]
Life cycles, such as those of plants, with alternating haploid and diploid phases can be referred to as diplohaplontic (the equivalent terms haplodiplontic, diplobiontic or dibiontic are also in use). Life cycles, such as those of animals, in which there is only a diploid phase are referred to as diplontic. (Life cycles in which there is only a haploid phase are referred to as haplontic.) ]
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