Question

Nucellus forms which of the following parts of fruit?
A. Seed coat
B. Perisperm
C. Seed
D. Raphe

Answer 1

Hint:- Nucellus is present at the center of an ovule in which embryo sac is there and it forms a nutritive tissue layer in the seed of flowering plants which surrounds the embryo in embryo sac.

Complete step-by-step solution:- First of all, you should know what nucellus is. Nucellus is the central part of an ovule which contains female gametophyte or embryo sac and there are changes in the seeds seen after fertilisation which are-
There is development of pericarp which is the outermost covering of the fruit and it is developed by the ovary wall.
There is development of outer covering of seed coat which is called testa from integument.
The inner integument gets developed into the inner covering of the seed coat which is called tegmen.
Zygote gets developed into the embryo.
There is development of ovary into fruit and the development of ovule into seeds.
There is formation of perisperm which is a nutritive tissue formed by nucellus.
If we look at options now, option A is seed coat. This is an incorrect option since the seed coat is not formed by nucellus but it is developed by integuments and thus this option gets eliminated.
Moving to option B which is Perisperm. This option is the correct one as perisperm is the layer of nutritive tissue which surrounds the embryo and it is formed by nucellus. Therefore, this option is correct.
Moving to option C which is Seed. This option is incorrect as ovule is developed into seed, nucellus does not form seed. Therefore, this option is incorrect.
Last option D is Raphe. This is an incorrect option since raphe is not formed by nucellus and therefore this option gets eliminated.
Thus, the correct answer is option B which is Perisperm.

Note:- There are post fertilisation changes seen in seeds in which the seed coat is developed from integuments, pericarp is developed from ovary wall, perisperm is developed from nucellus. Perisperm is the layer of nutritive tissue formed by nucellus and thus perisperm is the correct option.