Module: | Double Fertilization & Endosperm
Q84: Consider the following statements regarding the caruncle and seed dispersal in castor:
1. The mature seed of the castor plant features a distinct, white, spongy outgrowth at the micropylar end known as the caruncle.
2. The caruncle is highly rich in lipids and sugars, serving as an ecological reward to attract ants for seed dispersal, a process called myrmecochory.
3. Anatomically, the caruncle is derived from the rapid post-fertilization proliferation of the inner integument at the chalazal pole.
Which of the above statements is/are correct?
2. The caruncle is highly rich in lipids and sugars, serving as an ecological reward to attract ants for seed dispersal, a process called myrmecochory.
3. Anatomically, the caruncle is derived from the rapid post-fertilization proliferation of the inner integument at the chalazal pole.
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 contains multiple anatomical errors.
The castor seed (Ricinus communis) possesses a highly specialized appendage.
Structurally, at the narrow end of the seed (the micropylar end), a white, bilobed, spongy mass develops, termed the caruncle.
Causally, it serves two main functions: it acts like a sponge to absorb water rapidly during germination, and it is an elaiosome (a lipid-rich attachment). This lipid reward drives myrmecochory, where foraging ants carry the heavy seed back to their nests, eat the caruncle, and discard the intact seed in nutrient-rich soil.
Statement 3 is structurally false.
The caruncle does not originate from the chalazal pole, nor does it come from the inner integument.
It strictly develops from the proliferation of the cells of the outer integument directly at the micropylar opening.
The castor seed (Ricinus communis) possesses a highly specialized appendage.
Structurally, at the narrow end of the seed (the micropylar end), a white, bilobed, spongy mass develops, termed the caruncle.
Causally, it serves two main functions: it acts like a sponge to absorb water rapidly during germination, and it is an elaiosome (a lipid-rich attachment). This lipid reward drives myrmecochory, where foraging ants carry the heavy seed back to their nests, eat the caruncle, and discard the intact seed in nutrient-rich soil.
Statement 3 is structurally false.
The caruncle does not originate from the chalazal pole, nor does it come from the inner integument.
It strictly develops from the proliferation of the cells of the outer integument directly at the micropylar opening.