The pollen tube usually enters the embryo sac
(1) through one of the synergids
(2) by directly penetrating the egg
(3) between one synergid and central cell
(4) by knocking off the antipodal cells
In an embryo sac, the cells that degenerate after
fertilisation are
(1) Synergids and primary endosperm cell
(2) Synergids and antipodals
(3) Antipodals and primary endosperm cell
(4) Egg and antipodals
Which of the following options is correct?
1. | Pollination gives the guarantee of the promotion of post-pollination events that lead to fertilization |
2. | The events – “from pollen deposition on stigma until pollen tubes enter the ovule" are together referred to as pollen-pistil interaction |
3. | Pollen-pistil interaction is a dynamic process involving pollen recognition followed by only promotion (not rejection) of the pollen |
4. | Pistil has no ability to recognize the pollen, whether right or wrong type |
Which of the following statements is not correct?
(1) Insects that consume pollen or nectar without bringing about pollination are called pollen nectar robbers
(2) Pollen germination and pollen tube growth are regulated by chemical components of pollen interacting with those of the pistil
(3) Some reptiles have also been reported as pollinators in some plant species
(4) Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style
The entry of pollen tube into the embryosac takes place due to the chemo-attractant secreted by
1. Tapetum
2. Oosphere
3. Filiform apparatus
4. Antipodal