Question

Pollens or aero:allergens enter the atmosphere from
1) Grass
2) trees
3) weeds
4) All of the above

Answer 1

Answer: (d) All of the above

Explanation:

Pollens or aero are the seeds of plants, weeds or trees which are released into the atmosphere by them during the period of pollination.

When plants are ready to pollinate and want to release their pollens in order to transfer them to the female plant, transfering them through air is a way adopted by unisexual plants.

These pollens or aeros are nothing but the seeds of plants which can be a cause of allergies to some human beings and animals.

Answer 2

Pollens or aero allergens enters from to the atmosphere through Grass, trees and weeds (i.e.) all the above options give us pollen and aeroallergens.  

Pollen is a male gamete of the plant that travels through different medium such as air, water etc. to fuse with the female gamete of another plant in order to give rise to a zygote.

These pollens are extremely small and thereby they enter the respiratory tract of the humans and cause allergies.