Chlorophyceae are commonly known as green algae because they contain chlorophyll a and b, which give them a green colour. They are mostly found in freshwater habitats.
2. The plant body of Chlorophyceae may be:
Correct Answer: C
Members of Chlorophyceae (green algae) show a wide range of structural organization. Their plant body may be unicellular (like Chlamydomonas), colonial (like Volvox) or filamentous (like Ulothrix and Spirogyra).
3. Chlorophyceae appear grass green due to the presence of:
Correct Answer: A
Members of Chlorophyceae are green in colour due to the dominance of chlorophyll a and chlorophyll b pigments. These pigments help in photosynthesis and give them their characteristic grass green appearance.
4. In green algae, photosynthetic pigments are localised in:
Correct Answer: B
In Chlorophyceae (green algae), pigments such as chlorophyll a and b are present in definite chloroplasts. These organelles carry out photosynthesis and help in food production.
5. Chloroplasts in Chlorophyceae may have shapes such as:
Correct Answer: A
In Chlorophyceae, chloroplasts show a wide variety of shapes depending on the species. These include discoid, plate-like, reticulate (network-like), cup-shaped, spiral and ribbon-shaped forms, reflecting structural diversity among green algae.
6. Storage bodies present in chloroplasts of most Chlorophyceae are called:
Correct Answer: A
Most members of Chlorophyceae have storage bodies called pyrenoids located within their chloroplasts. These structures are associated with the storage of starch and help in photosynthetic efficiency.
7. Pyrenoids contain:
Correct Answer: C
Pyrenoids are storage bodies present in the chloroplasts of many green algae. They contain proteins along with starch, and are associated with carbohydrate storage and photosynthesis.
8. In some algae, food is stored in the form of:
Correct Answer: B
While many algae store food as starch, some algae store reserve food in the form of oil droplets. These oil reserves act as an energy source and help the organism survive under unfavorable conditions.
9. The cell wall of green algae is mainly composed of:
Correct Answer: A
Green algae (Chlorophyceae) have a rigid cell wall. It consists of an inner layer made of cellulose and an outer layer made of pectose. This structure provides strength and protection to the algal cells.
10. Vegetative reproduction in algae occurs by:
Correct Answer: A
Vegetative reproduction in algae commonly occurs by fragmentation, where the thallus breaks into pieces, or by the formation of various types of spores. These methods help algae multiply rapidly in favorable conditions.
11. Asexual reproduction in algae occurs by flagellated zoospores produced in:
Correct Answer: B
In algae, asexual reproduction commonly occurs through the formation of flagellated zoospores. These zoospores are produced inside specialized structures called zoosporangia and help in dispersal in aquatic environments.
12. Sexual reproduction in algae may be:
Correct Answer: A
Sexual reproduction in algae shows variation in the type and formation of gametes. It can be isogamous (gametes similar in size), anisogamous (gametes dissimilar in size) or oogamous (large non-motile female gamete and small motile male gamete).
13. Which of the following are examples of green algae (Chlorophyceae)?
Correct Answer: A
Common examples of green algae (Chlorophyceae) include Chlamydomonas (unicellular), Volvox (colonial), Ulothrix and Spirogyra (filamentous), and Chara (more complex form). These represent different levels of organization within green algae.