Plant reproduction often requires pollen.
Hay fever or pollen allergy is the most prevalent allergy.
Plant reproduction often requires something that causes allergies.
What is required for plant reproduction?
[a] By wind and rain
[b] Something that is found on a cloud
[c] fertilization occurs
[d] Males and females
[e] Something that comes from a volcano
[f] Something that is invisible
[g] Something that causes allergies
[h] sperm and egg fuse