Which one of the following statements is wrong? [2015]
Chlorella and Spirulina are used as space food.
Mannitol is stored food in Rhodophyceae.
Algin and carrageenan are products of algae.
Agar-agar is obtained from Gelidium and Gracilaria.
(2)
Laminarin and mannitol are food reserves of brown algae or Phaeophyceae. Rhodophycean algae store food in the form of Floridean starch.
Male gametes are flagellated in [2015]
Ectocarpus
Spirogyra
Polysiphonia
Anabaena
(1)
Ectocarpus produces biflagellate gametes. Anabaena is a cyanobacteria and does not reproduce sexually. Spirogyra produces non-flagellated male gametes during conjugation, where the entire cell content functions as a gamete. Polysiphonia also produces non-flagellated spermatia.
Which one of the following is wrong about Chara? [2014]
Upper oogonium and lower round antheridium
Globule and nucule present on the same plant
Upper antheridium and lower oogonium
Globule is male reproductive structure
(3)
All species of Chara reproduce sexually and show highly advanced oogamy. The sex organs are the most distinctive features of the Order Charales and are the most complicated among the thallophytes. Male and female gametangia are called antheridia and oogonia, respectively. Male fructification (cluster of antheridia) is called globule, and the female is nucule. They are borne at the nodes of short branches, globule towards the lower side and nucule (female structure) towards the upper side.
Which one of the following shows isogamy with non-flagellated gametes? [2014]
Sargassum
Ectocarpus
Ulothrix
Spirogyra
(4)
Sexual reproduction in algae takes place through the fusion of two gametes. In Spirogyra, the gametes are similar in size (isogamy) and non-flagellated (non-motile).
