Module: | Double Fertilization & Endosperm
Q85: Consider the following statements regarding the specialized haustoria of the endosperm:
1. In certain angiosperms, the developing endosperm forms aggressive, specialized outgrowths called haustoria to maximize nutrient absorption.
2. In the plant Grevillea, the chalazal end of the endosperm develops into a prominent, invasive vermiform (worm-like) appendage.
3. These haustorial structures are strictly composed of maternal diploid cells derived directly from the nucellus tissue.
Which of the above statements is/are correct?
2. In the plant Grevillea, the chalazal end of the endosperm develops into a prominent, invasive vermiform (worm-like) appendage.
3. These haustorial structures are strictly composed of maternal diploid cells derived directly from the nucellus tissue.
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 intrinsically incorrect regarding ploidy and origin.
The primary function of the endosperm is to feed the embryo.
In many plants, especially those with cellular or helobial endosperm, simply absorbing local nutrients is insufficient.
Structurally, the endosperm produces haustoria, finger-like or tubular extensions that aggressively invade surrounding maternal tissues (integuments or funicle) to siphon off nutrients.
A classic, highly tested botanical example is Grevillea robusta (Silver Oak), where the chalazal portion of the endosperm elongates into a massive, coiled, worm-like (vermiform) appendage.
Statement 3 fails the genetic origin test.
These haustoria are not maternal nucellar cells.
Because they are direct physical extensions of the endosperm itself, they are post-fertilization structures and are inherently triploid (3n) in their genetic makeup.
The primary function of the endosperm is to feed the embryo.
In many plants, especially those with cellular or helobial endosperm, simply absorbing local nutrients is insufficient.
Structurally, the endosperm produces haustoria, finger-like or tubular extensions that aggressively invade surrounding maternal tissues (integuments or funicle) to siphon off nutrients.
A classic, highly tested botanical example is Grevillea robusta (Silver Oak), where the chalazal portion of the endosperm elongates into a massive, coiled, worm-like (vermiform) appendage.
Statement 3 fails the genetic origin test.
These haustoria are not maternal nucellar cells.
Because they are direct physical extensions of the endosperm itself, they are post-fertilization structures and are inherently triploid (3n) in their genetic makeup.