1. | Algae are chlorophyll-bearing, thalloid, autotrophic and largely aquatic (both fresh water and marine) organisms. |
2. | Algae are chlorophyll-bearing, having highly differentiated body, autotrophic and exclusively found in fresh water organisms. |
3. | Algae are chlorophyll-bearing or parasitic heterotrophic organisms, thalloid and largely marine organisms. |
4. | Algae are chlorophyll-lacking, thalloid, autotrophic and largely saprophytic organisms found in both fresh and marine waters. |
The form and size of algae is highly variable. Which of the following will not be true?
I: | Volvox is a colonial alga. |
II: | Ulothrix and Spirogyra do not form filaments. |
III: | Kelps form massive plants bodies. |
1. Only II | 2. Only III |
3. Both I and II | 4. Both II and III |
Identify the incorrectly matched pair:
Alga | Sexual reproduction | |
I: | Ulothrix | Isogamous; non-flagellated gametes |
II: | Spirogyra | Isogamous; flagellated gametes |
III: | Udorina | Anisogamous |
IV: | Fucus | Oogamous |
1. | Only III | 2. | I, II and III |
3. | Only I and II | 4. | Only III and IV |
I: | Gametes are flagellated and similar in size in Ulothrix |
II: | Gametes are non-flagellated and similar in size in Spirogyra |
III: | Gametes are dissimilar in size in Eudorina |
Sexual reproduction takes place through non flagellated gametes that are similar in size in:
1. | Ulothrix | 2. | Spirogyra |
3. | Volvox | 4. | Fucus |
Oogamous sexual reproduction is seen in:
1. | Ulothrix | 2. | Spirogyra |
3. | Udorina | 4. | Fucus |
Fusion of two gametes which are dissimilar in size is termed as
1. | Oogamy | 2. | Isogamy |
3. | Anisogamy | 4. | Zoogamy |
I: | At least a half of the total carbon dioxide fixation on earth is carried out by algae through photosynthesis. |
II: | They are of paramount importance as primary producers of energy-rich compounds which form the basis of the food cycles of all aquatic animals. |
III: | Many species of Porphyra, Laminaria and Sargassum are among the 70 species of marine algae used as food. |
IV: | Agar, one of the commercial products obtained from Gelidium and Gracilaria, are used to grow microbes and in preparations of ice-creams and jellies. |
V: | Chlorella, a multicellular alga rich in proteins, is used as food supplement even by space travellers. |
Which of the following is not an example of an edible alga?
1. | Porphyra | 2. | Laminaria |
3. | Sargassum | 4. | Amanita |
I: | Algin is a hydrocolloid derived from brown algae |
II: | Carrageen is a hydrocolloid derived from green algae |
III: | Agar is a complex polysaccharide derived from red algae, Gelidium and Gracilaria |