Which of the following options accurately defines perisperm in relation to a flowering plant seed?

Remnant of the nucellus

The correct answer is Option (4) - Remnant of the nucellus

Perisperm refers to the remnant of the nucellus, which is the tissue present within the ovule of a flowering plant. It is the part of the seed that surrounds and is distinct from the embryo and endosperm.

In the life cycle of a flowering plant, after fertilization occurs, the zygote develops into an embryo, and the central cell of the embryo sac develops into the endosperm. The endosperm is a triploid tissue that provides nourishment to the developing embryo.

In some plant species, the nucellus surrounding the embryo sac also undergoes changes after fertilization. The nucellus degenerates or breaks down, and its remnants become the perisperm. The perisperm is a part of the seed that persists and surrounds the embryo and endosperm.

Unlike the endosperm, which is a product of double fertilization involving the fusion of one sperm with the central cell, the perisperm is derived from the maternal tissue (nucellus) and is not involved in the process of double fertilization.

Therefore, perisperm is the remnant of the nucellus, and option (4) is the correct answer.