What is exine and entine?

Exine is the outer layer. It is tough and resistant due to presence of tough substance called sporopollenin. Intine is inner to the exine and it resembles plasma membrane in structure. So, exine and intine are the parts of the pollen grain. So, the correct answer is ‘Pollen grain’.

What is called exine?

(ĕk′sēn′, -sīn′) The outer layer of the wall of a spore or pollen grain.

What is the function of exine and intine?

The exine is developed through the contribution of the early microspore cytoplasm and the inner anther wall cell layer, the tapetum, which plays a dominant role in the synthesis and deposition of sporopollenin on the pollen grain outer surface. Therefore exine synthesis and patterning are under sporophytic control.

What is intine and exine made up of?

The intine layer is made up of cellulose and pectin materials. The exine is hard and hence protects the pollen grains during adverse conditions. Detailed Answer:Exine is made up of a substance called sporopollenin while intine is made up of pectocellulose.

What is intine in pollen?

The intine, the inner layer of the pollen wall, is essential for the normal development and germination of pollen.

What is intine in biology?

Intine: It is the inner layer as clear from the name. It is made up of cellulose (hemicellulose) and Pectin. It is less resistant as compared to excine. > Excine: It is the outer layer of pollen grain.

What is intine function?

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.

Where is exine located?

5 Exine Architecture Exine is commonly divided into the outer sculptured sexine and the sim- pler inner nexine, located just above the intine (Figure 2a,d).

What is exine in biology class 12?

Excine: It is the outer layer of pollen grain. It is extremely resistant to cold, heat, bases and thus forms a chemical material named sporopollenin.

What role does the Tapetum play?

Tapetum is the innermost cell layer in the anther, which surrounds the developing pollen mother cells (PMCs) and/or microspores supplying nutrition and enzymes required for microsporogenesis and pollen maturation.

What is generative cell?

[ jĕn′ər-ə-tĭv ] A cell of the male gametophyte (pollen grain) of seed plants that divides to give rise directly or indirectly to sperm.

Is intine continuous?

Intine is a thick, non-continuous inner layer of pollen grain.

What is the difference between the intine and exine layer?

The intine, or inner layer, consists primarily of cellulose and pectins. The exine, or outer layer, is composed of a highly decay-resistant chemical called sporopollenin. The exine usually has one or more thin areas, or pores, through which the pollen tubes germinate, and the…

What is the difference between exine and intine pollens?

Exine is the outermost covering of pollens composed of a very hard organic substance Sporopollenin(in fact one of the the hardest organic substance ).fossilisation of pollens are possible due to this hard covering. Intine is the inner covering of pollens and are relatively soft. Pollen grain has a prominent two layered wall.

What is the exine of a plant made of?

The exine, or outer layer, is composed of a highly decay-resistant chemical called sporopollenin. The exine usually has one or more thin areas, or pores, through which the pollen tubes germinate, and the….

When does the intine develop in a cell?

The intine usually starts to develop at the vacuolated stage, beneath the apertures. It increases in thickness under the pores and later on starts to develop under the interapertural parts as a thin layer. Golgi bodies are frequent during intine synthesis e.g., Ranunculaceae while in others, E.R. and polyribosomes are abundant e.g. Cosmos.

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