Question

Crassinucellate ovule shows
A. Absence of nucellus
B. Well-developed nucellus
C. Partially developed nucellus
D. Ill developed nucellus

Answer 1

Hint:In the early development of the megasporocyte two or more cell layers are present between the megasporocyte and the epidermal cells.

Complete answer:
The ovule is the structure that produces the female reproductive cells in plants. It comprises three sections: the integument, which forms its exterior layer, the nucellus, and in the middle the female gametophyte.
The ovule is found in the floral section called the gynoecium in flowering plants. In gynoecium the ovary develops one or more ovules and gradually becomes the wall of the fruit. The ovule seems to be a megasporangium with integuments. Ovules are first composed of the maternal diploid tissue, which contains a megasporocyte.
Megaspores remain within the ovule to create the Haploid female gametophyte or megagametophyte, which remains also inside the ovule, by mitosis. The megagametophytes are surrounded by the remains of the megasporangium tissue (nucellus). Archegonia develop megagametophytes that create egg cells. The ovule produces a diploid zygote after fertilisation and, until the cell division starts, an embryo from the next generation of sporophytes.
Crassinucellate ovule shows well-developed Nucellus. In the early development of the megasporocyte two or more cell layers are present between the megasporocyte and the epidermal cells. The megasporocyte develops into an embryo sac containing the egg that develops into the embryo if fertilized and under the suitable conditions.

Thus, the correct answer is option B. i.e., Well-developed nucellus.

Note:The nucellus form part of the internal structure of the ovule and immediately develop a layer of diploid cells within the integuments. It is similar to the megasporangium structurally and functionally.