Life Science: Chapter 1 - Plant and Animal Classification

CLASSIFICATION OF PLANTS

• Entire plant kingdom is divided into Cryptogamae (Non-flowering) and Phanerogamae (Flowering) depending upon the presence or absence of flowers and seeds.

Cryptogamae (Kryptos: concealed; Gamus: Marriage)

• It includes non-flowering plants such as algae, fungi, lichens, mosses and ferns.
• Classified in three parts: 

1. Thallophyta (Comes from thallus: plant body not differentiated into root, stem, body and leaves)
2. Bryophyta (Amphibian of plant kingdom) - They lack roots, flowers and seeds but root like structure rhizoids are present.
3. Pteridophyta - They have primitive vascular system.

Phanerogamae (Phaneros: Visible; Gamus: Marriage)

• They are divided into two parts:

1. Gymnospermae (Naked Seed)
2. Angiospermae (Covered Seed)

CLASSIFICATION OF ANIMALS

• When any plane passing through the central axis of the body divides the organism in two halves that are approximately mirror images it is called radial symmetry and the animals showing radial symmetry are called Radiata.
• When the body can be divided into identical left and right halves in only one plane, this kind of symmetry is called bilateral symmetry and such animals are called Bilateria.
• Animals are mainly classified into two parts: Invertebrates (animals with backbone) - Almost 99% animals fall in this group and Vertebrates (animals with backbone).
• Animals are also classified as Chordates (animals in which notochord is present) and Non-Chordates (animals in which notochord is absent).