Botany and Plant Science

Grafting is not possible in monocots as they lack cambium as it helps in binding the two parts of the stem.

Ovule integument gets transformed into seed coat. It is The outer protective covering of a seed.,Also called testa.

Primary wall is elastic due to the absence of lignin. Lignin is water-resistant. It reinforces cell walls, keeping them from collapsing.

Collenchyma occurs in the climbing stems. They provide structural support, protecting the plant by serving as an inner framework. Plants are exposed to numerous structural challenges and without these cells, most plants would be too fragile to withstand the damage caused by heavy rains, high winds and other stresses.

In sclerenchyma, wall is lignified. Due to lignification, the cells lose their living characters at maturity.

 In aquatic plants, parenchyma cells have star like air cavities in between the cells. They are called aerenchyma. The air trapped in the cavities make the plants lighter in weight and help them to float in water.

 Collenchyma is a mechanical tissue with unlignified walls.These cells are often found under the epidermis, or the outer layer of cells in young stems and in leaf veins.

Xanthophylls are the typical yellow pigments of leaves. A green leaf is green because of the presence of a pigment known as chlorophyll, which is inside an organelle called a chloroplast. Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue depending on the pH. Melanin is a class of compounds that serves as a pigment with different structures responsible for dark, tan, yellowish/reddish pigments in marine animals. 

 Phloem tissue conducts prepared food from the leaf to storage organs and growing regions.Phloem tissue consists of: conducting cells, generally called sieve elements; parenchyma cells, including both specialized companion cells or albuminous cells and unspecialized cells; and supportive cells, such as fibres and sclereids.

 A ‘thallus’ refers to plant body having no distinction of stem, leaves and roots.

Naked seed condition of gymnosperms stands in contrast to the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary.  

In angiosperms (dicots), the Polygonum type of embryo sac is the most common. In this embryo sac, the arrangement of the nuclei is 3 + 2 + 3, i.e. 3 in antipodal cells, 2 in polar nuclei (which later fuse and form a diploid secondary nucleus) and 3 in egg apparatus (2 in synergids and 1 in egg cell).

In angiosperms, male gametophyte consists of a tube cell and a generative cell. The generative cell divides to form two male gametes.

Micropyle is the narrow passage left by the integuments at one end of the ovule. It allows the entry of pollen tube into the ovule. This phenomenon is known as porogamy. For example, lily.

This is an incorrect option as pollen wall does not have cavities containing proteins.