Botany and Plant Science

Cambium is the layer which forms Cork and acts as a secondary meristem from a layer of collenchyma or parenchyma immediately beneath the epidermis. The cells which produce from cork cambium will differentiate and will get mature to perform a specialized function. The living cells which lost the capacity to divide can regain the capacity of the division under certain conditions is called as 'Dedifferentiation.'

 Xylem cells are dead and elongated hollow cells consists of secondary cell wall contains lignin.

If a plant is flashed with red light initially and then flashed with far red light, the effect of red light is reversed. It is due to the presence of phytochromes which are present in plants as the pigments for light absorption. It has two forms, Pr and Pfr. The range of absorption in wavelength is from 660 nm to 730 nm.

In Leucosolenia, Gemmule formation (also called  internal budding ) occurs to tide over seasonal drought  or other adverse environmental conditions .

The cells derived from root apical and shoot apical meristems and cambium differentiate and mature to perform specific functions. This process leading to maturation of cells is termed as differentiation. During differentiation, cells undergo few to major structural changes both in their cell walls and protoplasm e.g., to form a tracheary element the cells would lose their protoplasm, they also develop strong, elastic, lignocellulosic secondary cell walls, to carry water to long distances even under extreme tension. So, the correct answer is 'All of the above'.

Interfascicular cambium is the cambium formed by dedifferentiation of cells forming the ground tissue (parenchyma) that lie in line to the vascular cambium, since these strips of cambium originate between two vascular bundles or connect two vascular cambia together they are referred to as the interfascicular cambia. They are responsible for producing medullary rays during secondary growth.

Redifferentiation is the formation of new or differentiated tissue from a already differentiated tissue. During this process cells of parenchymatous tissue undergo dedifferentiation to meristematic tissue. The cells cut off by the meristematic tissue based on the location and function get modified to respective tissues like secondary cortex, secondary xylem and secondary phloem in roots, monocot stem, cork cells etc

The cells derived from root apical and shoot-apical meristems and cambium differentiate and mature to perform specific functions. This act leading to maturation is termed as differentiation. During differentiation, cells undergo few to major structural changes both in their cell walls and protoplasm. The living differentiated cells, that by now have lost the capacity to divide can regain the capacity of division under certain conditions. This phenomenon is termed as dedifferentiation. For example, formation of meristems – interfascicular cambium and cork cambium from fully differentiated parenchyma cells. While doing so, such meristems / tissues are able to divide and produce cells that once again lose the capacity to divide but mature to perform specific functions, i.e., get redifferentiated. 

Crown of a tree is basically the aerial part of trees that contains branches, leaves and stems. Thus, it constitutes the branchy part of trees.

Parenchyma is a versatile ground tissue that generally constitutes the "filler" tissue in soft parts of plants. It forms, among other things, the cortex and pith of stems, the cortex of roots, the mesophyll of leaves, the pulp of fruits, and the endosperm of seeds. Parenchyma cells are living cells and may remain meristematic at maturity—meaning that they are capable of cell division if stimulated. They have thin and flexible cellulose cell walls, and are generally polyhedral when close-packed, but can be roughly spherical when isolated from their neighbours. They have large central vacuoles, which allow the cells to store and regulate ions, waste products, and water. Tissue specialised for food storage is commonly formed of parenchyma cells.

Laticiferous vessels are the specialized thin walled parenchymatous cells that secrete latex and are found in the cortex. They lack pits and are composed of cellulose and hemicelluloses and serve to secrete latex. 

On the basis of location and function, three main tissue systems are found in plants, dermal, vascular, and ground tissue. Dermal tissue is composed of epidermal cells, closely packed cells that secrete a waxy cuticle that aids in the prevention of water loss. The primary components of vascular tissue are the xylem and phloem. The ground tissue of plants includes all tissues that are neither dermal nor vascular. The three types of ground tissue, parenchyma, collenchyma, and sclerenchyma, function in photosynthesis, storage, regeneration, support, and protection.

Medullary ray is a band of parenchyma in the secondary xylem extending into the secondary phloem of the stems of certain vascular plants, formed by the cambium and helps for the storage of food and conduction of nutrients. it helps in the gaseous exchange through the intercellular spaces.