Ch 3Plant Kingdom — Class 11 Biology, concept-first.

Plants show an astonishing range of body forms -- from a single microscopic cell drifting in a pond, to a mat of moss on a damp wall, to a towering conifer that lives for centuries.

Algae are chiefly aquatic, chlorophyll-bearing organisms whose plant body is a thallus -- meaning it is never differentiated into a true root, stem and leaves, however large or complex that thallus ma…

Bryophyta -- from the Greek bryon (moss) and phyton (plant) -- are simple land plants of moist, shaded habitats.

Pteridophyta -- from the Greek pteron (feather) and phyton (plant), reflecting the feather-like, pinnately divided leaves of many of its members -- were, evolutionarily, the first plants to become tru…

Gymnospermae -- from the Greek gymnos (naked) and sperma (seed) -- are seed-bearing plants whose seeds are not enclosed within a fruit, unlike those of flowering plants.

Every plant's life cycle unfolds across two alternating generations: the diploid sporophyte (2n) and the haploid gametophyte (n), linked to each other by two key events -- meiosis and fertilisation.

This chapter classified the plant kingdom into four major groups on the basis of spore- versus seed-formation, the presence or absence of vascular tissue, and how far the plant body is differentiated…