give the reasons for dominance of angiosperm on earths surface?
There are variety of reasons for dominance of angiosperm on Earth's surface due to the following:
1.Reproductive structures and processes.
1.Reproductive structures and processes.
- Seed production as means of reproduction and dispersal
- Flower the flower lures insects, birds, bats to itself, and in the process has dramatically increased the diversity of flowering plants. Co-evolution (mutual adaptation) with insects. Insures cross-pollination with members of the same species by utilizing only a relatively small amount of pollen compared to the large amounts of pollen necessary in random wing pollination. As a result, angiosperm flowers, derived from leaves modified into sepals, petals, and related structures, are amongst the most intricate and attractive organs that veer appeared in plants.
- Closed carpels allow seeds to develop enclosed within a fruit protecting seeds from desiccation as they grow and mature, and aids in the dispersal of seeds.
- Double fertilization which results in the production of endosperm, a nutritive tissue that feeds the developing embryo.
- Vascular system
- Flowering plants possess very efficient water conducting cells, called vessel elements, in their xylem, in addition to tracheids. (Gymnosperms xylem consists on tracheids exclusively).
- Leaves
- The leaves of flowering plants, with their broad, expanded blades, are structured for maximum efficiency in photosynthesis.
- Abscission of these leaves during cold or dry spells reduces water loss and thus has enabled some flowering plants to expand into habitats that would otherwise be too harsh for survival.