NCERT Solutions for Class 11 Biology Chapter 3 Plant Kingdom

Short Note:

• Algae are chlorophyll-bearing, simple, thalloid, autotrophic, largely aquatic organisms, classified into Chlorophyceae (green algae), Phaeophyceae (brown algae), and Rhodophyceae (red algae) based on pigments and stored food.

• Bryophytes (amphibians of the plant kingdom) include mosses and liverworts; they need water for fertilisation and show a dominant gametophyte stage.

Short Note:

• Pteridophytes (e.g. ferns) have well-differentiated plant body into root, stem and leaves, with vascular tissue; the sporophyte is the dominant, independent phase, unlike in bryophytes.

Short Note:

• Gymnosperms ('naked seed' plants) have seeds that are not enclosed within a fruit, e.g. Pinus, Cycas.

• Angiosperms (flowering plants) have seeds enclosed within a fruit; classified into monocotyledons and dicotyledons based on the number of cotyledons in the seed.

• Double fertilisation, unique to angiosperms, involves fusion of one male gamete with the egg (forming the zygote) and another with the two polar nuclei (forming the triploid endosperm).

Short Note:

• Plants show alternation of generations — a haploid gametophytic (gamete-producing) phase alternates with a diploid sporophytic (spore-producing) phase in the life cycle.