Difference Between Exine and Intine

Answer: The pollen grain is made up of two layer exine and intine. Exine constitutes the hard outer layer, which is made up of sporopollenin, which is the most resistant material to be known. And intine is the thin inner layer of the pollen grain, which is made up of cellulose and pectin.

1. What is meant by Exine?
2. What is the role of Intine?
3. What is the Exine made up of?
4. Where is Exine found?
5. Where do the pollen germinate naturally?
6. Which plays an important role in guiding the pollen tube into Synergid?
7. What are the specific terms used for inner and outer walls of pollen grains?
8. Where is Sporopollenin found?
9. Which one is generally absent in Germpores?
10. Which is generally absent in germ pores?
11. Which came first angiosperms or gymnosperms?

What is meant by Exine?

: the outer of the two major layers forming the walls of some spores and especially pollen grains.

What is the role of Intine?

The intine layer, which is located between the exine of the pollen wall and the cell membrane, is essential for the maturation of the pollen grain and pollen tube germination.

What is the Exine made up of?

While the exine is composed of sporopollenin, a complex and highly resistant biopolymer containing fatty acids, phenylpropanoids, phenolics and carotenoids, the intine is largely composed of pectin and cellulose.

Where is Exine found?

The intine is the innermost layer, which is composed primarily of cellulose and pectins, resembling the primary cell wall of a typical parenchyma cell. The exine is the hard, outermost, desiccation-resistant wall layer that provides the major structural support for the cytoplasm.

Where do the pollen germinate naturally?

The pollen grains germinate naturally on the stigma of compatible flower. They develop pollen tubes that helps to deliver sperm nuclei inside the embryo sac where fertilization takes place.

Which plays an important role in guiding the pollen tube into Synergid?

The filiform apparatus is believed to play a major role in pollen tube guidance and reception. It has also been assumed that the pollen tube enters the receptive synergid cell through the filiform apparatus.

What are the specific terms used for inner and outer walls of pollen grains?

Explanation: In general, pollen grains have a double wall consisting of a thin inner wall composed of cellulose, termed the endospore, and a thick outer wall comprised of sporopollenin, termed the exospore.

Where is Sporopollenin found?

Sporopollenin is a lipid- and phenolic-based polymer present in the outer exine layer of pollen walls (Morant et al., 2007). Similarly, suberin is a lipid- and phenolic-based polymer present in the cell walls of various external and internal tissue layers (Franke & Schreiber, 2007).

Which one is generally absent in Germpores?

Pollen grain has prominent apertures called germ pores where sporopollenin is absent. what is the function of germ pore? germ tube is the origin site for pollen tube. germ pore gives rise to pollen tube which carries the male gamete to the to the ovary for fertilisation.

Which is generally absent in germ pores?

Germ pore is the opening found in pollen, where exine (outer wall) is absent. Was this answer helpful?

Which came first angiosperms or gymnosperms?

The first angiosperms must have evolved from one of the gymnosperm species that dominated the world at the time. The Amborella genome suggests that the first angiosperms probably appeared when the ancestral gymnosperm underwent a 'whole genome doubling' event about 200 million years ago.