Botany and Plant Science

It is characterised by morphologically dissimilar spores that are produced from two types of sporangia. These are microspores or male spores and megaspores (macrospores) or female spores. The arrangement of the young leaves within a bud is vernation. In cycas, circinate vernation is there.

The sporogonium of Funaria is photosynthetic. It has stomata present on its seta part. Seta is a long stalk with a pear-shaped capsule by its tip.

During its transit inside the pollen tube, the generative cell divides to form two male gametes. The third cell is the pollen tube cell.

In Polygonum type of development, the functional megaspore passes through three mitotic divisions to produce a seven-celled embryo sac.

A bract is a modified or specialised leaf, especially the one associated with a reproductive structure such as a flower.

Thigmotropism is the directional response of a plant organ to touch or physical contact with a solid object. It is best seen in leaves or tendrils.

It is completely inverted so that the micropyle is facing downwards and situated near the base of the funiculus. It is the most common type of ovule found in angiosperm (all plants of gamopetalae).

Wolffia, a hydrophyte, is the smallest angiospermic flower known.

In gymnosperms, female meiocyte undergoes meiosis and four unequal megaspores are formed in a linear tetrad.

Some genera have ovules that are rotated at right angle to their stalk. This is called twisting or torsion and is the characteristic of solanaceae.

Microsporophyll is a leaf-like structure that bears microsporangia. Hence, it is a male structure.

The development of an embryo without the occurrence of fertilisation is called apomixis.

Monocarpellary ovary means having single carpel. Diadelphous androecium means stamens are united in two bundles and marginal placentation means that there is only one elongated placenta on one side of the ovary, as ovules are attached at the fusion line. This is the characteristic of family papillionaceae.

Transfer of pollen from anther to stigma is called pollination. Each pollen grain is a male haploid gametophyte, adapted to being transported to the female gametophyte, where it can effect fertilisation by producing the male gamete (or gametes, in the process of double fertilisation). 

 Fruits are formed from ovary of the flowers.