helps in fertilization, so water is not essential for fertilization. • Double fertilization is present. The endosperm is triploid. • Angiosperms are broadly classified into two classes namely Dicotyledons and Monocotyledons.
. . Characteristic features of Dicotyledons and Monocotyledons Dicotyledons Morphological features Reticulate venation is present in the leaves. Presence of two cotyledons in the seed.
Primary root radicle persists as tap root. Flowers tetramerous or pentamerous. Tricolpate ( furrow) pollen is present. Anatomical features • Vascular bundles are arranged in the form of a ring in stem.
• Vascular bundles are open (Cambium present). • Secondary growth is present. Monocotyledons Morphological features Parallel venation is present in the leaves. Presence of single cotyledon in the seed.
Radicle doesn’t persist and fibrous root is present. Flowers trimerous. Monocolpate ( furrow) Pollen is present. Anatomical features • Vascular bundles are scattered in the stem • Vascular bundles are closed (Cambium absent).
• Secondary growth is absent. Current Angiosperm Phylogeny Group (APG) System of classification doesn’t recognize dicots as a monophyletic group. Plants that are traditionally classified under dicots are dispersed in several clades such as early Magnolids and Eudicots . Summary Plant Kingdom includes Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms The life cycle in plants fall under three types .
Haplontic, . Diplontic and . Haplodiplontic Algae are autotrophic, chlorophyll bearing organisms. The Plant body is not differentiated into root like, stem like or leaf like structures.
A wide range of thallus organization is found in algae. They reproduce vegetatively through fragmentation, tuber and akinete formation. Zoospores, autospores and hypnospores are produced during asexual reproduction and sexual reproduction occurs through isogamy, anisogamy and oogamy. Bryophytes are the simplest land plants.
They are called amphibians of plant kingdom or nonvascular cryptogams. The plant body is gametophyte. The sporophyte depends upon gametophyte. Conducting tissues like xylem and phloem is absent.
Vegetative reproduction takes place through fragmentation, formation of adventitious bud and gemmae. Sexual reproduction is oogamous. Water is essential for fertilization. Pteridophytes are also called vascular cryptogams.
The plant body is sporophyte and is long lived, which is differentiated