Module: | Double Fertilization & Endosperm
Q73: Consider the following statements regarding the formation and function of Ubisch bodies:
1. Ubisch bodies are microscopic, lipid-rich structures secreted exclusively by the cells of the secretory tapetum.
2. They are primarily composed of sporopollenin precursors that are deposited onto the maturing microspores to help construct the exine.
3. In the fully mature pollen grain, Ubisch bodies remain permanently embedded within the inner intine layer to provide structural flexibility.
Which of the above statements is/are correct?
2. They are primarily composed of sporopollenin precursors that are deposited onto the maturing microspores to help construct the exine.
3. In the fully mature pollen grain, Ubisch bodies remain permanently embedded within the inner intine layer to provide structural flexibility.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, whereas Statement 3 is strictly incorrect.
The tapetum is critical for pollen wall formation.
In the glandular (secretory) tapetum, cells synthesize pro-Ubisch bodies, which are lipid droplets.
Once these are coated with sporopollenin, they are extruded into the anther locule as Ubisch bodies (or orbicules). Causally, these bodies transport and deposit the highly resistant sporopollenin polymer onto the developing exine (outer wall) of the microspores.
Statement 3 is a structural falsehood.
Sporopollenin and Ubisch bodies have absolutely no association with the intine.
The intine is the inner wall, synthesized directly by the microspore itself, and is composed entirely of cellulose and pectin to allow for the eventual protrusion of the pollen tube.
The tapetum is critical for pollen wall formation.
In the glandular (secretory) tapetum, cells synthesize pro-Ubisch bodies, which are lipid droplets.
Once these are coated with sporopollenin, they are extruded into the anther locule as Ubisch bodies (or orbicules). Causally, these bodies transport and deposit the highly resistant sporopollenin polymer onto the developing exine (outer wall) of the microspores.
Statement 3 is a structural falsehood.
Sporopollenin and Ubisch bodies have absolutely no association with the intine.
The intine is the inner wall, synthesized directly by the microspore itself, and is composed entirely of cellulose and pectin to allow for the eventual protrusion of the pollen tube.