Why pollen grains can remain well-preserved as fossils?

When pollen grains are directly received by ovules in the pollen chamber, it is………… .

Exine of pollen grains is made up of

An anther has 1200 pollen grains. How many pollen mother cells must have been there to produce them?

Remanants and impressions of organisms that remain preserved underground.

Even though each pollen grain has 2 male gemetes, why at least 20 pollen are required to fertilise, 20 ovules in carpel?

______________ is the transfer of pollen grains from anther of the flower to the stigma of the same or a different flower

Ginkgo biloba is called as living fossil. Why?

After Pollination,if the 2-celled pollen grain comes across dry stigma, then there will not be germination of pollen grain. Give reason.

Pollen grains are formed by meiotic division in locules of anthers.

Name the layer which supplies nourishment is the developing pollen grains. OR Name teh layer which supplies nourishment to the developing pollen grains.