• How-do-plants-know-when-to-flower
    Biology,  Botony

    How do plants know when to flower?

    Phytochrome, a blue-green pigment, is part of a switching mechanism for phototropic responses to light of red and far-red wavelengths. Its active form, Pfr might trigger the secretion of one or more hormones that induce and inhibit flowering at different times of yeat. The main environmental cue for flowering is the length of night, i.e. the hours of darkness, which vary seasonally. Different kinds of plants from flowers at different times of years, depending on their phytochrome mechanism. Products of a set of master gene govern flower formation by selectively acting on meristematic cells of floral shoots. The study of mutants of common wall cress, Arsbidopsis thaliana, supports an ABC…

  • Botony,  Video Notes

    ANGIOSPERMS (FLOWERING PLANTS)

    https://youtu.be/XF6WSXqI-ks Angiosperms are most dominant and most evolved plants on this earth, appeared about 130 million years ago in Jurassic (dicot plant) and cretaceous (monocot plants) period of the Mesozoic era. Tertiary period of Cenozoic era is called as Age of angiosperms. Angiosperms are found in every habitat. They constitute more than 50% of the total plants on this earth. Angiosperms are seed bearing, flowering vascular plants in which seeds are enclosed in fruits. The term angiosperm means ‘enclosed seeds’ as seeds (ovules) are found enclosed in the ovary wall. Instead of a cone, angiosperms bear flowers. The flower is the most characteristic structure of the angiosperms. The flower is…