Module: | Pre-fertilization: Micro/Megasporogenesis
Q18: Consider the following statements regarding the Primary Endosperm Cell (PEC) and its ploidy:
1. Following double fertilization, the central cell of the embryo sac becomes the Primary Endosperm Cell (PEC).
2. The PEC develops into the endosperm, whose cells are typically triploid (3n) in angiosperms.
3. The primary endosperm nucleus (PEN) undergoes successive meiotic divisions to form the highly nutritious free-nuclear endosperm.
Which of the above statements is/are correct?
2. The PEC develops into the endosperm, whose cells are typically triploid (3n) in angiosperms.
3. The primary endosperm nucleus (PEN) undergoes successive meiotic divisions to form the highly nutritious free-nuclear endosperm.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, but Statement 3 is strictly incorrect.
After the triple fusion event, the massive central cell housing the triploid PEN transforms into the Primary Endosperm Cell (PEC). The PEC is structurally dedicated to forming the endosperm, a nutrient-rich tissue that sustains the developing embryo.
Because it originates from the fusion of three haploid nuclei, its ploidy level is triploid (3n). Statement 3 fails the biological mechanism test: the PEN undergoes rapid, successive mitotic divisions, not meiotic divisions, to multiply its nuclei without reducing its ploidy.
Meiosis only occurs during the formation of spores (microspores and megaspores) prior to fertilization.
Understanding the sequence of mitotic events in the PEC is a fundamental learning objective in developmental botany.
After the triple fusion event, the massive central cell housing the triploid PEN transforms into the Primary Endosperm Cell (PEC). The PEC is structurally dedicated to forming the endosperm, a nutrient-rich tissue that sustains the developing embryo.
Because it originates from the fusion of three haploid nuclei, its ploidy level is triploid (3n). Statement 3 fails the biological mechanism test: the PEN undergoes rapid, successive mitotic divisions, not meiotic divisions, to multiply its nuclei without reducing its ploidy.
Meiosis only occurs during the formation of spores (microspores and megaspores) prior to fertilization.
Understanding the sequence of mitotic events in the PEC is a fundamental learning objective in developmental botany.