Botany and Plant Science

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. 

The lactation period is the period of milk production after the birth of a calf when the lactation period has increased the production of milk also increases.

• Turmeric has some antioxidant and anti-inflammatory properties and Basil is used for stomach spasms, loss of appetite, intestinal gas but they come under herbs, not a tree.
  
• Oak is mainly used for furniture purposes as Oak wood is exceedingly strong, heavy and durable.
  
• Neem tree has various medicinal properties such as antioxidant, anti-inflammatory, anti-diabetic, anticancer, antifungal, antiviral. 
• So, option A neem is the correct answer.
  

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.

• The roots that arise horizontally from the primary roots which provide anchorage to the plants and fixes it into the soil. 
• These roots help in the uptake of water and nutrients from the soil which is required for the growth and development of the plants.
  
• They are endogenous in nature as it is developed from the cells of the pericycle which become meristematic and undergoes periclinal (parallel to the surface of a part) and anticlinal (right angles to the surface) division.
• So, the correct answer is 'Pericycle'.

• Passage cells are also known as transfusion cells.
• They are thin-walled cells which lack suberin and are found in the endodermis (is the central innermost layer of the cortex) of vascular plants (plants which consist of vascular tissues i.e, xylem and phloem).
• They are located opposite the protoxylem strands or elements.
• They are found in the endodermis of dicots.
• So, the correct answer is 'Protoxylem elements'.

Passage cells forms the endodermis of older roots of monocots. They are thin walled and have casparian strips, unlike the other cells that becomes suberized and waterproof. Passage cells function to allow transfer of solutes into the stele, in order to eventually reach the transpiration system.

Pericycle is a primary tissue of plant roots and is the site for the initiation of lateral roots and two secondary meristems, the vascular cambium and cork cambium (phellogen). 

The layers of cells lying between endodermis and vascular bundle is pericycle. The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Although it is composed of non-vascular parenchyma cells, it is still considered part of the vascular cylinder, because it arises from the procambium as do the vascular tissues it surrounds.

Passage cells are endodermal cells of older roots which have retained thin walls and Casparian strips rather than becoming suberized and waterproof like the other cells around them, to continue to allow some symplastic flow to the inside (cortex to pericycle). 

In the stem, the pith and the cortex make up the ground tissue. The pith is located within the cylinder of vascular tissue, where it often exhibits a spongy texture because of the presence of large intercellular air spaces. If the growth of the pith fails to keep up with that of the surrounding tissues, the pith may degenerate, producing a hollow stem. In general, roots lack piths, although there are exceptions to this rule.