Question

Zoospores produced in the Ectocarpus are?
(1) Motile
(2) Thick-walled
(3) Pyriform
(4) Both (1) and (3)

Answer 1

Ectocarpus is a marine brown algae, which are distributed across the temperate and tropic seas. The plant body is filament type and has basal rhizoids, and also has a well developed branched erect system. Reproduction may be isogamous, anisogamous or oogamous type.

Complete answer:
Ectocarpus reproduces both by a sexual and asexual method. Asexual reproduction takes place by the formation of biflagellate Zoospores. These Zoospores can be both haploid or diploid. The diploid Zoospores is made by a diploid multicellular body called Plurilocular Sporangia. The haploid Zoospores is formed by Unilocular sporangia. These Zoospores are produced asexually. Throughout the liberation, the Apex of the sporangia walls gets dissolved and the Zoospores are liberated in a thick gelatinous mass and swim freely in the water.
They move to the suitable substratum and release the flagellum and then a new cell is formed around it.

So the right answer is A (motile).

Additional Information: The reproduction in Ectocarpus is both sexually and asexually. The sexual reproduction is both isogamous and anisogamous. Oogamy is absent in ectocarpus. Usually, anisogamy is very common among them. Anisogamy may be of two varieties: morphological anisogamy (E. Secundus) and physiological anisogamy (E. siliculosus). The gametes are produced inside the plurilocular gametangia, developed on haploid plants. Ectocarpus belongs to the Phylum Ochrophyta, and class Phaeophyceae and Order Ectocarapales and the Family Ectocarpaceae.

Note:
A few species of Ectocarpus also occur in freshwaters. The plant grows attached to rocks and stones along the coasts. Some species are epiphytes on other algae like members of Fucales and Laminaria. fasciculatus grows on the fins of certain fish in Sweden. Ectocarpus dermonemcnis is endophytic. Ectocarpus carver and Ectocarpus spongiosus are free-floating.