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Genetic Evidence Suggests That Homosporous Ferns with High Chromosome Numbers are Diploid -- Haufler and Soltis 83 ... (384 words) |
 | Homosporous ferns have usually been considered highly polyploid because they have high chromosome numbers (average n = 57.05). |
| Therefore, homosporous ferns either have gone through repeated cycles of polyploidy and gene silencing or were initiated with relatively high chromosome numbers. |
| The latter possibility represents a radical departure from currently advocated hypotheses of fern evolution and suggests that there may be fundamental differences between the genomes of homosporous ferns and those of higher plants. |
| lab7 (2085 words) |
| In homosporous plants usually a large number of sporocytes from the central tissue of the developing sporangium undergo meiosis to produce numerous spores. |
| When homosporous spores germinate to produce the multicellular haploid gametophyte, these gametophytes germinate and continue to grow outside of the confines of the spore wall, and establish themselves as independent ("free living") plants. |
| In contrast to the situation in homosporous plants, where the gametophyte is produced outside of the spore wall upon germination, the micro- and megagametophytes are produced within the micro- and megaspore walls, respectively. |
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