Draw a diagram of a male gametophyte of an angiosperm. Label any four parts. Why sporopollenin is considered the most resistant organic material?

Following is the labelled diagram of a male gametophyte of an angiosperm.




Sporopollenin is considered to be the most resistant organic material because it is chemically very stable and it can withstand high temperatures, acidic and alkaline conditions, and enzymes. No enzyme that degrades sporopollenin is so far known.