NEETBotanyMorphology of Flowering Plants
In a mature seed of black pepper, what is the correct sequence of ploidy levels for its perisperm, endosperm, and cotyledon respectively?
Options
- An, 3n, 2n
- B2n, 3n, 2n
- C3n, 3n, 2n
- D2n, 2n, 2n
Correct answer
B. 2n, 3n, 2n
Step-by-step solution
In black pepper, the perisperm represents the persistent nucellus. Since the nucellus is a maternal sporophytic tissue, it is diploid ( 2n ). The endosperm in angiosperms is formed by the primary endosperm nucleus (PEN) via triple fusion, making it triploid ( 3n ). The cotyledon is a part of the embryo, which develops from the zygote formed by syngamy, making it diploid ( 2n ). Therefore, the correct sequence of ploidy levels is 2n, 3n, 2n . Answer: 2n, 3n, 2n