Module: | Pre-fertilization: Micro/Megasporogenesis
Q27: Consider the following statements regarding the perisperm in mature seeds:
1. The perisperm represents the persistent, residual remnants of the nucellus that are not entirely consumed during seed development.
2. Black pepper and beet are standard botanical examples of seeds that retain a prominent perisperm.
3. Because it develops alongside the endosperm, the perisperm is genetically triploid (3n) in its cellular makeup.
Which of the above statements is/are correct?
2. Black pepper and beet are standard botanical examples of seeds that retain a prominent perisperm.
3. Because it develops alongside the endosperm, the perisperm is genetically triploid (3n) in its cellular makeup.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, while Statement 3 is fundamentally incorrect regarding ploidy.
During typical ovule development, the massive nucellus tissue is usually consumed entirely by the expanding embryo sac and later the endosperm.
However, in a few specific evolutionary lines, structurally represented by black pepper and beet, remnants of the nucellus persist into the mature seed.
This residual, nutritive tissue is called the perisperm.
Statement 3 fails the genetic origin test: the endosperm is triploid (3n) because it results from the triple fusion of two polar nuclei and a male gamete.
The nucellus, conversely, is purely maternal, somatic sporophytic tissue.
Therefore, the perisperm, being derived directly from the nucellus, is strictly diploid (2n). Testing the ploidy difference between endosperm and perisperm is a high-yield exam concept.
During typical ovule development, the massive nucellus tissue is usually consumed entirely by the expanding embryo sac and later the endosperm.
However, in a few specific evolutionary lines, structurally represented by black pepper and beet, remnants of the nucellus persist into the mature seed.
This residual, nutritive tissue is called the perisperm.
Statement 3 fails the genetic origin test: the endosperm is triploid (3n) because it results from the triple fusion of two polar nuclei and a male gamete.
The nucellus, conversely, is purely maternal, somatic sporophytic tissue.
Therefore, the perisperm, being derived directly from the nucellus, is strictly diploid (2n). Testing the ploidy difference between endosperm and perisperm is a high-yield exam concept.