Read the following statements and choose the set of correct statements. [2024]
In the members of Phaeophyceae,
A. Asexual reproduction occurs usually by biflagellate zoospores
B. Sexual reproduction is by oogamous method only
C. Stored food is in the form of carbohydrates, which is either mannitol or laminarin
D. The major pigments found are chlorophyll a, c, carotenoids, and xanthophyll
E. Vegetative cells have cellulosic walls, usually covered on the outside by a gelatinous coating of algin.
Choose the correct answer from the options given below:
A, B, C, and D only
B, C, D, and E only
A, C, D, and E only
A, B, C, and E only
(3)
Sexual reproduction in Phaeophyceae may be isogamous, anisogamous, or oogamous.
Which classes of algae possess pigment fucoxanthin and pigment phycoerythrin, respectively? [2023]
Phaeophyceae and Chlorophyceae
Phaeophyceae and Rhodophyceae
Chlorophyceae and Rhodophyceae
Rhodophyceae and Phaeophyceae
(2)
Phaeophyceae vary in color from olive green to various shades of brown due to the presence of varying amounts of the xanthophyll and fucoxanthin pigment. The members of Rhodophyceae are commonly called red algae because of the predominance of the red pigment, r-phycoerythrin, in their body.
Which of the following is incorrectly matched? [2022]
Ectocarpus - Fucoxanthin
Ulothrix - Mannitol
Porphyra - Floridean starch
Volvox - Starch
(2)
Ulothrix is a member of Chlorophyceae. The stored food material in Ulothrix is starch. Mannitol is the stored food material for members of Phaeophyceae.
Hydrocolloid carrageen is obtained from [2022]
Chlorophyceae and Phaeophyceae
Phaeophyceae and Rhodophyceae
Rhodophyceae only
Phaeophyceae only
(3)
Hydrocolloid carrageen is obtained from Rhodophyceae alga Chondrus crispus.
Which of the following algae produce Carrageen? [2021]
Blue-green algae
Green algae
Brown algae
Red algae
(4)
Carrageen is obtained from red algae Chondrus crispus and is used as a pharmaceutical emulsifier, cleaning agent, and in the textile, leather, and brewing industry.
Which of the following algae contains mannitol as reserve food material? [2021]
Ulothrix
Ectocarpus
Gracilaria
Volvox
(2)
Mannitol is reserve food material in Phaeophyceae, e.g., Ectocarpus.
Floridean starch has structure similar to [2020]
starch and cellulose
amylopectin and glycogen
mannitol and algin
laminarin and cellulose
(2)
In Rhodophyceae, food is stored as Floridean starch, which is very similar to amylopectin and glycogen in structure.
Which of the following pairs is of unicellular algae? [2020]
Laminaria and Sargassum
Gelidium and Gracilaria
Anabaena and Volvox
Chlorella and Spirulina
(4)
Gelidium, Gracilaria, Laminaria, and Sargassum are multicellular. Anabaena is filamentous blue-green algae. Volvox is colonial.
An example of colonial alga is [2017]
Volvox
Ulothrix
Spirogyra
Chlorella
Which one of the following statements is wrong? [2016]
Algae increase the level of dissolved oxygen in the immediate environment.
Algin is obtained from red algae, and carrageenan from brown algae.
Agar-agar is obtained from Gelidium and Gracilaria.
Laminaria and Sargassum are used as food.
(2)
Alginic acid is obtained from brown algae, whereas carrageenan is obtained from red algae.
