Question

Which one of the following statements is not true?
A) Tapetum helps in the dehiscence of anther
B) Exine of pollen grains is made up of sporopollenin
C) Pollen grains of many species cause severe allergies
D) Stored pollen in liquid nitrogen can be used in the crop breeding programmes

Answer 1

Hint: It is a specialized nutrient cell layer of flowering plants contained within the anther, in which it is situated between the sporogenous tissue and the wall of the anther.

Complete Answer:
Pollen is a powdery material that creates male gametes composed of pollen grains that are male microgametophytes in seed plants. Pollen grains have a tough coat composed of sporopollenin that shields the gametophytes from the stamens to pistil in flowering plants as well as from the male cone to its female coniferous plants during the period of their flight.

Now, let us find the solution from the options-
- Tapetum is the inner lining of the sporogenous tissue which entirely covers it. Tapetum cells have a thick cytoplasm and normally get more than one nucleus. The developing pollen grains are nourished by Tapetum. Alpha cellulose and fragments of lignin compose these thickenings. These thickenings become hygroscopic and thus aid in the dehiscence of anthers.
- Exine is the outer coating of a finely sculpted pollen grain of sporopollenin; an unreactive carotenoid ester polymer that, as known so far, is finely difficult to degrade by any enzyme. Thus, option B is not the correct option.
- One of the most important causes for seasonal allergies is pollen. The pollen allergy is known to many people as "hay fever." People with allergies to pollen only get problems when they are exposed to pollen in the air. Thus, option C is not the correct option.
- Pollen grains have been preserved in liquid nitrogen for several years and have a temperature of -196°C. Cryopreservation is the name of this form of preserving. The low temperature enables for a longer time of storage as it decreases the rate of cell expansion. The cryoprotective agents slow the plants' ageing and defend the plants from cold-related damage. Thus, option D is not the correct option.

Thus, the correct answer is option (A) Tapetum helps in the dehiscence of anther.

Note: Endothecium is the layer of the anther wall that aids in anther dehiscence. Endothecium cells produce fibrous thickenings that radiate from the inner tangential walls at maturity.