life cycle of fucus
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Answer:Life history and early reproductive stages in the genus Fucus. The sexual life cycle is gametic; the free-living stage is diploid, and the only haploid stages are the gametes. The gametes (1) are produced in the receptacles, from which they are then released and fertilization is external. After fertilization, the egg produces an adhesive by which it attaches to the substrate (2). The egg polarizes according to the prevailing light direction, is attached further by a rhizoid cell that develops by the first cell division (3), and develops into a germling (4). Fucus vesiculosus is dioeciuos (female at the left and male at the right in the picture). Gametic life cycles occur within the Fucales, whereas in most other brown algae a free-living diploid stage alternates with a freeliving haploid stage (South and Whittick, 1987; Kropf, 1997). Scale bar = 1 mm for phases 1-3, and 15 mm for adult individuals.