Q.Give three reasons why pteridophytes are considered structurally more advanced than bryophytes.

Pteridophyta ('feather-plants') were, evolutionarily, the first plants to combine true vascular tissue (xylem of tracheids, phloem of sieve cells, but no cambium and hence no secondary growth) with a genuinely differentiated root, stem and leaves -- making them the first true vascular land plants, even though they still reproduce by spores rather than seeds.

The sporophyte is diploid, autotrophic and fully independent -- the plant we recognise as 'the fern' -- bearing true adventitious roots (the short-lived primary root is soon replaced) and leaves that are either small with a single unbranched vein (microphylls, e.g. Selaginella) or large and often pinnately compound with branched veins (macrophylls/fronds, e.g. Nephrolepis, Dryopteris). Fertile fronds bear sori -- clusters of spore-producing sporangia -- typically on their undersurface.

The gametophyte is a separate, small, short-lived, independent, non-vascular structure (a flat prothallus in ferns) bearing antheridia and archegonia; as in bryophytes, fertilisation still needs a film of water for the motile antherozoids to reach the egg. Pteridophytes are classified into Psilopsida, Lycopsida, Sphenopsida and Pteropsida, and are valued medicinally, for soil-binding, and as ornamentals.