Answer : (c)

Answer : (b)

Answer : (b)

Answer:(a)

Answer:(d)

Answer:(c)

Answer:(d)

Answer:(c)

Answer:(b)

Interfascicular cambium develops from the cells of medullary rays. Answer:(a)

Lenticels are lense like opening in periderm developed during secondary growth. Answer:(b)

Number of annual rings = Number of Years Answer:(c)

Answer:(c)

Answer:(a)

Cork cambium undergoes periclinal division and cuts off thick walled suberised dead cork cells towards outside and it cuts off thin walled living cells i.e., phelloderm on inner side. Answer:(c)

In roots, the root hairs arise from zone of maturation. This zone is differentiated zone thus bearing root hairs. Answer:(a)

Cellulose microfibrils are oriented radially rather than longitudinally which makes easy for the stoma to open. Answer:(c)

During secondary growth, vascular cambium gives rise to secondary xylem and secondary phloem. Phelloderm is formed by cork cambium. Answer:(c)

Heartwood is physiologically inactive due to deposition of organic compounds and tyloses formation, so this will not conduct water and minerals. Answer:(c)

Answer : (c)

Bulliform cells are the large thin-walled, empty cells that occur in the epidermis of many grass leaves and that by their turgor changes cause rolling and unrolling of the leaves thus regulating water loss. When bulliform cells are flaccid, the leaves of grass close as the two sides of the blade fold up toward each other. Once adequate water is available, the leaves open again. When folded, the leaves are less exposed to sunlight, so they are heated less which prevents water loss. Answer : (b)

Growth rings are formed by the seasonal activity of cambium. In plants of temperate regions, cambium is more active in spring and less active in autumn seasons. In temperate regions climatic conditions are not uniform throughout the year. However in tropics climatic conditions are uniform throughout the year. Answer : (d)

Phloem in Gymnosperms lacks both sieve tube and companion cells. Answer : (d)

Answer : (c)

Answer : (b)

Answer : (d)

Primary meristematic cells arise from the promeristem and make up the apical tip (present at the shoot tip) as well as the root promeristem Answer : (b)

In grafting cambium helps in binding the two parts of the stem. Monocots do not posseses cambium hence grafting is not possible in monocots. Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots. Answer : (a)

A vessel element or vessel member (trachea) is one of the cell types found in xylem, the water conducting tissue of plants. Vessel elements (tracheae) are typically found in flowering plants (angiosperms) but absent from most gymnosperms Answer : (a)

Endodermis of dicot stem, is unilayered innermost cortex made from more or less barrel shaped compactly arranged parenchymatous tissues. It store starch and often called starch sheath. Answer : (b)

Laticiferous vessels are the specialized thin walled parenchymatous cells that secrete latex and are found in the cortex. Answer : (c)

Apical meristems give rise new tissues that lenghens the stems of grasses. Apical meristems are located at the apices or tips - at root and shoot tips and are directly involved in their elongation They create derivatives which form primary growth. Intercalary meristems at the nodes of bamboo allow for rapid stem elongation, while those at the base of most grass leaf blades allow damaged leaves to rapidly regrow Answer : (c)

In the dicot stem, the vascular bundles are arranged in a ring, with pith concentrated at the core of the stem Answer : (d)

Xylem parenchyma is the only living component of the xylem tissue. Parenchyma cells stay alive, typically helping produce and store nutrients. They are capable of cell division if stimulated. Answer : (c)

Tyloses (singular – tylosis) are the balloon like outgrowth of parenchymatous cells to the lumen of tracheids or vessels of the secondary xylem. The axial and ray parenchyma of the xylem develops protrusion and these protrusions enter or invade into the lumen of tracheids or vessels through pits. Answer : (a)

Botanically term wood is used for secondary xylem produced due to activity of cambium in the stem. In angiosperms (dicots) the wood is said to be hard or porous. Hard wood is made up of vessels, xylem fibres and xylem parenchyma. Answer : (c)

Bicollateral vascular bundles are a type of conjoint vascular bundle with the xylem situated in the inner strand of the phloem and are present in the stem. Bicollateral vascular bundles are present in Cucurbitaceae family, examples Pumpkin, Ridge gourd. Answer : (b)

In plants undergoing secondary growth, the pericycle contributes to the vascular cambium often diverging into a cork cambium. Answer : (c)

Vascular bundles are conjoint, collateral, open and arranged in a ring (eustele). Each bundle is composed of outer phloem and inner xylem on the same radius with a strip of cambium in between them (open type). The xylem is endarch (i.e. protoxylem lie towards the pith, while metaxylem lies towards periphery). Vascular bundles Closed, collateral, endarch vascular bundles found in monocot stem Some important Characteristic Features of dicot stem are : 1. Epidermis with out growth. 2. Hypodermis collenchymatous. 3. The ground tissue gets differentiated into cortex, endodermis , pericycle, medullary rays and pith. 4. Vascular bundles are limited in number. 5. Vascular bundles are arranged in the form of a broken ring. 6. Cambium is seen in between xylem and phloem. Hence the bundles are open. 7. Phloem parenchyma is present. 8. Xylem vessels are arranged in a linear fashion. 9. Protoxylem lacunae absent. 10.Vascular bundles have sclerenchymatous bundle cap. Answer : (a)

Ray parenchyma cells occur in wood rays, the structures that transport materials laterally within a woody stem. Parenchyma cells also occur within the xylem and phloem of vascular bundles. The largest parenchyma cells occur in the pith region, often, as in corn (Zea ) stems, being larger than the vascular bundles. Radial conduction refers to the conduction of water in the horizontal direction through the xylem. It takes place by the ray parenchymatous cells of xylem Answer : (d)

In plants with floating leaves, stomata may be found only on the upper epidermis and submerged leaves may lack stomata entirely. Answer : (b)

The wall of both the vessel and sieve tube elements are perforated by large openings. Due to these adaptation the cell to cell contact is possible. Answer : (d)

Secondary meristems are responsible for secondary growth, or increase in stem girth and thickness. Secondary meristems form a new from other cells in injured tissues and are responsible for wound healing. Answer : (b)

Trichomes are hair like appendages on leaves and stems of plants. A major function of the trichome is thought to be in plant defense against insects. Chemicals produced in the glandular tip can deter feeding or the trichome can physically prevent the insect from reaching and feeding on the leaf. They can also reduce the rate of transpiration by blocking air flow across the leaf surface Answer : (b)

Diagnostic Features of Dorsiventral Leaf Hypostomatic - stomata are present only on lower epidermis option "b" correct Differentiated Mesophyll - into upper palisade parenchyma and lower spongy parenchyma Hypodermal Collenchyma - between bundle sheath of midrib vein and the upper and lower epidermal layers Conjoint, collateral Vascular bundles - with endarch xylem Vessels and tracheids - in metaxylem and protoxylem Lower epidermis contains numerous stomata without chloroplast; while upper epidermis contains high amount of chloroplast and no stomata, thus the leaf is hypostomatic Answer : (b)

Collenchyma cells are usually living, and have only a thick primary cell wall made up of cellulose and pectin. Answer : (a)

The vascular cambium is responsible for increasing the diameter of stems and roots and for forming woody tissue Answer : (c)

companion cell A type of cell found within the phloem of flowering plants. Each companion cell is usually closely associated with a sieve element. Its function is uncertain, though it appears to regulate the activity of the adjacent sieve element and to take part in loading and unloading sugar into the sieve element Answer : (d)

Intercalary meristems are capable of cell division, and they allow for rapid growth and regrowth of many monocots. Primary growth is a result of rapidly dividing cells in the apical meristems at the shoot tip and root tip. Subsequent cell elongation also contributes to primary growth. The growth of shoots and roots during primary growth enables plants to continuously seek water (roots) or sunlight (shoots). Answer : (b)

Lacunar or Tubular Collenchyma Lacunar collenchyma consist thickening around the cell walls facing the cavity lumen or intracellular spaces. Examples :petioles of Family: Lamiaceae examples Leucas, Salvia, basil, mint, rosemary, sage, savory, marjoram, oregano, hyssop, thyme, lavender, and perillaetc. Angular collenchyma is found in - Datura, Solanum, Helianthus, Cucurbita, etc collenchyma cells are classified into four main types: angular, tangential, annular, and lacunar. Answer : (a)