Tag: structure of male and female reproductive structures

In seed plants, Ovule is the part of the female reproductive organ. It consists of three parts; Integument ( forming its outer layer) Embryo sac ( female gametophyte) and a Nucellus that is the central and largest part of the ovule as a source of nutrients for the embryo and its ploidy is diploid i.e 2n
Nucellus is derived from the apical portion of the ovule primordium of the ovule primordium and function as a megasporangium i.e, the nucellus produces the megasporocyte, which will undergo meiosis to form megaspores that is the reason that nucellus of the ovule is diploid in nature.
So, the nucellus of ovule is diploid.

So, the correct answer is 'Megasporangium'

The ovule of flowering plants are located inside the gynoecium and are connected to the placenta which is a parenchymatous tissue via a stalk-like structure called the funiculus.

A. Female gametes are also called eggs or ovum. They are created during the cellular reproduction process known as meiosis. The resulting gamete cell is a haploid cell.

When in a flower, the internode between the corolla and the androecium is lengthened so as to raise the androecium high up in the air then that internode is called Androphore. It is an extension of the receptacle carrying the androecium and the gynoecium, typical of the caper family. In Passiflora, androphore is lightly differentiated.

When pollen tube enters through the micropyle, the phenomenon is known as porogamy. When pollen tube enters to the embryo sac through the tissue of the chalaza, the phenomenon is known as chalazogamy. When pollen tube enters through the base of a funiculus or the integument, the phenomenon is known as mesogamy. Isogamy is a form of sexual reproduction that involves fusion of gametes of similar size and structure. 

Ovule means 'small egg'. In seed plants, the ovule is the surface that gives rise to and contains the female reproductive cells. It consists of three parts: the integuments form its outer layers, the nucellus and female gametophyte in its center. The female gametophyte specifically termed as megagametophyte is also called the embryo sac in angiosperms.

The mature ovule contains in its central part a region called the nucellus that in turn contains an embryo sac with eight nuclei, each with one set of chromosomes. The two nuclei near the centre are referred to as polar nuclei. In the pines, the female gametophyte develops within the tissues of the nucellus and acquires abundant food reserves. The proembryo forms after a period of free-nuclear division in the zygote, and the tier of cells above the basal four then elongates to form a suspensor which pushes the embryonic group deep into the gametophyte.