Phytochrome occurs in two forms. In which form it promotes the germination of seeds of some species ?
Pfr forms
Pr forms
Both forms
None of these
A.
Pfr forms
Pfr form of phytochrome refers to physiologically active form whereas Pr form refers to inactive form.
Red light formation means the formation of Pfr. It helps in the induction of seed germination. On the contrary, far red light or Pr formation inhibits the germination.
Removal of top fertile soil by wind or water is :
Siltation
Soil erosion
Weathering of soil
Leaching
Seed which are able to withstand reduction in moisture and temperature are called
dormant seeds
recalcitrant seeds
orthodox seeds
non- viable seeds
Anthesis means
growth of pollen tube inside the carpel
dehiscence of anthers
opening of floral bud
emergence of anthers
Pollination occuring from one flower to another of same plant is :
autogamy
allogamy
geitenogamy
none of these