Short Answer TypeA pollen grain in angiosperm at the time of dehiscence from an anther could be 2-celled or 3-celled. Explain. How are the cells placed within the pollen grain when shed at a 2-celled stage ?
(a) Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi ? Provide explanations to your answer.
(a) It is possible by Artificial Hybridisation where pollen grain of one flower is introduced artificially on the stigma of another flower. But there should not be self-incompatibility.
* For this in One flower emasculation is removal of anthers & by choice by then flower is bagged.
* After some time, the bag is removed and then desired pollen grains are introduced on its stigma.
Long Answer Type(a) When a seed of an orange is squeezed, many embryos, instead of one are observed. Explain how it is possible.
(b) Are these embryos genetically similar or different ? Comment.
Short Answer TypeExplain the events up to double fertilisation after the pollen tube enters one of the synergids in an ovule of an angiosperm.
Multiple Choice QuestionsWhich one of the following statements is not true?
Exine of pollen grains is made up of sporopollenin
Pollen grains of many species cause severe allergies
Stored pollen in liquid nitrogen can be used in the crop breeding programmes
Stored pollen in liquid nitrogen can be used in the crop breeding programmes
In bryophytes and pteridophytes, transport of male gametes requires
insects
birds
water
water
Proximal end of the filament of stamen is attached to the
connective
placenta
thalamus
thalamus
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