Observe the diagram and answer the question.
The places where sporopollenin is not present on a pollen grain are known as:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Germ pores
Option (2) Germ pores — Correct. The pollen wall’s hard exine is made of sporopollenin, but at some places it is absent. These apertures are the germ pores, through which the pollen tube comes out.
NCERT Extract:
Stamen, Microsporangium and Pollen Grain – “… Pollen grains are generally spherical measuring about 25-50 micrometers in diameter. It has a prominent two-layered wall. The hard outer layer called the exine is made up of sporopollenin which is one of the most resistant organic material known. It can withstand high temperatures and strong acids and alkali. No enzyme that degrades sporopollenin is so far known. Pollen grain exine has prominent apertures called germ pores where sporopollenin is absent. Pollen grains are well-preserved as fossils because of the presence of sporopollenin.”