Seed which are able to withstand reduction in moisture and temperature are called
dormant seeds
recalcitrant seeds
orthodox seeds
non- viable seeds
C.
orthodox seeds
Orthodox seeds are the seeds that survive drying or freezing during ex- situ conservation. These are long- lived seeds and can be successfully dried to moisture contents.
A dormant seed is one that is unable to germinate in a specified period of time under a combination of environmental factors that are normally suitable for the germination of the non- dormant seed.
Recalcitrant seeds are seeds that do not survive drying and freezing during ex-situ conservation and vice versa.
Non- viable seeds are the seeds that do not germinate even if all the favourable conditions needed for germination are provided.
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
Removal of top fertile soil by wind or water is :
Siltation
Soil erosion
Weathering of soil
Leaching
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
