Biology - Chapter 3: Plant Kingdom
Understanding Plant Classification: From Algae to Flowering Plants
1. Classification of Plant Kingdom
| Group | Key Characteristics | Examples |
|---|---|---|
| Algae | Simple thallus body structure | Spirogyra |
| Bryophytes | Amphibious plants (require water for reproduction) | Moss |
| Pteridophytes | Vascular plants with true roots, stems, and leaves | Ferns |
| Gymnosperms | Seeds are naked (not enclosed in fruit) | Pinus |
| Angiosperms | Flowering plants with seeds enclosed in fruits | Mango |
2. Important Questions & Answers
Q1. Name the three main classes of Algae and their pigments.
Answer:
1. Chlorophyceae (Green Algae): Chlorophyll a and b
2. Phaeophyceae (Brown Algae): Chlorophyll a, c and Fucoxanthin
3. Rhodophyceae (Red Algae): Chlorophyll a, d and Phycoerythrin
1. Chlorophyceae (Green Algae): Chlorophyll a and b
2. Phaeophyceae (Brown Algae): Chlorophyll a, c and Fucoxanthin
3. Rhodophyceae (Red Algae): Chlorophyll a, d and Phycoerythrin
Q2. Why are Bryophytes called the amphibians of the plant kingdom?
Answer: Bryophytes live on land but require water for reproduction. The male gametes need water to reach the female reproductive organ.
Q3. What is Heterospory?
Answer: Heterospory refers to the formation of two types of spores: microspores and megaspores. It is an important step in the evolution of seed habit.
Q4. Differentiate between Gymnosperms and Angiosperms.
Answer:
Gymnosperms have naked seeds and do not form fruits, whereas Angiosperms have seeds enclosed within fruits and produce flowers.
Q5. What is the difference between Gametophyte and Sporophyte?
Answer:
Gametophyte is the haploid stage that produces gametes, whereas Sporophyte is the diploid stage that produces spores.
Q6. Which group shows double fertilization?
Answer: Double fertilization is a unique feature of Angiosperms. One male gamete forms the embryo, while the other forms the endosperm.