Chapter-8 Tissue and Tissue System (Knowledge based) 1.What is tissue? Ans: A group of similar and dissimilar cells originating from the same source and performing the similar function is known as tissue. 2.What is meristematic tissue? Ans:The tissue which are capable of cell division is called meristematic tissue. 3.What is primary meristematic tissue? Ans:At the apex of stem and root there is a short region from where the next meristematic tissue is originated is called primary meristematic tissue. 4.What is secondary meristematic tissue? Ans:The meristematic tissue which is originated from permanent tissue is called secondary meristematic tissue. 5.What is protoderm? Ans:The meristematic tissue which divides to produce the epidermis of different organs of plants is called protoderm. 6.What is procambium? Ans:The meristematic tissue which divides to produce vascular bundle is called procambium. 7.What is xylem? Ans:The complex tissue of plants which helps to transport water and mineral salts is called xylem. 8.What is cambium? Ans:The meristematic tissue which lies in between xylem and phloem is called cambium. 9.What is stomata? Ans: There is a special type of pore which is surrounded by guard cell found on the lower surface of dorsiventral leaf and on the either side of isobilateral leaf or in the tender stem is called stomata. 10.What is Tissue system? Ans:One or more types of tissue situated in a particular region when functions together as a unit, this combination of functional units is known as tissue system. 11.What is epidermis? Ans:The part of epidermal tissue system that forms the covering of root,stem,leaf,flower,fruit and seeds is called epidermis.Generally it one layered but may be multilayered.The skin of root is called epiblema and the skin of other organs is called epidermis.In the petals of flower and on the skin of fruit a pigment named anthocyanine is present. 12.What is Vascular tissue system? Ans: Xylem and phloem combindly form a system which is involved in the conduction of food and water in the plant body is known as vascular tissue system.It is also known as fascicular tissue system. 13.What is vascular bundle? Ans: Xylem and phloem exist together or in individual bundles. Such a bundle of xylem and phloem is called a vascular bundle. 14.Casparian strip: In the root, the peripheral or radical walls of endodermal cells remain surrounded by a strip formed by a deposition of lignin and suberin is known as casparian strip. 15.Stele: The central core of the stem and root of a vascular plant consisting of the vascular tissue and associated supporting tissue is known as Stele. 16.What is epiblema? Ans:The cuticleless outer covering of roots is called epiblema. 17.What is buliform cell? Ans:The larger cells with large vacuole and thin layered membrane which are found in grasses andin the leaves of some monocot plants are called Buliform cells. 18.What is Hydathode? Ans: Hydathod is the special pore located on the edge of the leaves of tomato, kachu and grass plants. 19. What is a pericycle? Ans: Pericycle is the tissue which is spread in one or more layers under the root skin. 20.What is a medulla? Answer: The tissue which is surrounded by stem or root vascular bundle and is located in the very center is called medulla. 21.What is Ground Meristem? Answer: The part of the apex dividing tissue that divides to form cortex, medulla and medullar ray is called ground meristem. 22.What is an epithem? Answer: The number of incoherent cells beneath the water vacuole in hydathode is called epithelium. 23. What is the interstitial zone? Answer: The whole inner part of stele is called interstitial zone. 24.What is the mass meristematic tissue? Answer: The dividing tissue cells that divide on all planes are called mass meristematic tissue. Examples are endosperm or plant tissue, medulla or medulla cortex, growing embryo, etc. 25. What is plate meristematic tissue? Ans: The cells of the dividing tissue which are divided into two planes, so that the cells become like plates, are called plate meristematic tissue. Examples- young leaves, growing epidermis etc. 26. What is rib meristematic tissue? Ans: The cells of the dividing tissue which are divided into a single plane are called rib meristematic tissue. Examples are growing roots, growing xylem and phloem tissues. Comprehensive 1.what do you mean by hydathode? Structurally modified portions of leaf which are meant to send out excess amount of water in liquid form is called Hydathode. It is a special type of water release organ. There is a cavity below the pore. under the cavity There are many incoherent cells called epithelium or epithelium. Below the epithelium lies the end of the trachea. 2.what is stomata? An ultramicroscopic pore that is found in the epidermis of leaves, stems, and other organs, and bordered by a pair of specialized parenchyma cells known as guard cells is called a stomata. Function of stomata is given below: # During respiration, O2 enters the air and CO2 is emitted. # During photosynthesis CO2 from the air enters the pores and the generated O2 is expelled. # The water collected by the roots evaporates with the help of transpiration. # Chloroplasts of guard cells prepare food. 3.explain vascular bundle. The bundle of xylem and phloem tissue together is called the vascular bundle. In vascular bundle xylem transports water and dissolved mineral salts From the roots to wherever it is needed. On the other hand, phloem transforts food produced in leaves in every cell. The vascular bundle is divided into three parts based on the mutual position of xylem and phloem. A) Radial vascular bundle. B) conjoint vascular bundle. C) concentric vascular bundle. 4.what do you mean by hydathode? Structurally modified portions of leaf which are meant to send out excess amount of water in liquid form is called Hydathode. It is a special type of water release organ. There is a cavity below the hydathode. under the cavity There are many incoherent cells called epithem or epithelium. Below the epithelium there lies the end of the trachea. 5.Write characteristics of meristematic tissue. Answer: The tissue that plants have the ability to divide cells is called meristematic tissue. Characteristics of meristematic tissue is given below: B) The walls of the cells are thin and made of cellulose and without design. C) The cells have the ability to divide. D) Cells are densely embedded so there is no intracellular gap between them E) The cells of meristem tissue are rectangular, oval, pentagonal or hexagonal in shape 6.what do you mean by bicollateral vascular bundle? Answer :When there is a phloem on the outside and inside of an conjoint vascular bundle, with cambium on either side of the xylem and xylem in the middle, it is called bicolateral vascular bundle. 7.Diagram of a stomata 8.Write difference between meristematic and permanent tissue. Answer: Difference between meristematic and permanent tissue is given below: 1. The cells are unable to divide. 2.They originate in the embryonic stage 3.Composed of immature cells 4.The size of the cells is indefinite 5.This tissue is found in the growing region 6.Cells do not have normal cavities, nucleus is in the center, cytoplasm is dense 7.All cells are alive. 8.It increases the number of cells in the plant body 1. The cells are capable of dividing. 2.They originate from meristematic tissue. 3.Composed of mature cells 4.The size of the cells is definite. 5.This tissue is found in the permanent region. 6.Cells have cavities, nuclei are circumferential, cytoplasm is light 7.Cells maybe alive or dead 8.It forms permanent areas in plant body. 9.Write difference between stomata and hydathode. Answer: Difference between stomata and hydathode is given below : Located on the upper and lower skin of the leaves Water vapor is emitted Mineral salts are not released with water Water emission is high during the day Controlled by guard cells. Epithem cell is present. 10.Difference between epidermis and epiblema. Located on the edge of the leaf Water is discharged in liquid form Mineral salts are released with water Water emission is high during the night Not controlled by guard cells Epithet cell is not present. Ans: Epidermis 1.It is present on the skin of stems and leaves. 2. The cuticle is present 3. There is stomata 4. Contains unicellular and multicellular trichomes 5. Function is protection and transpiration Epiblema It is located on the skin of the root.. The cuticle is absent There is no stomata There is no multicellular trichome The function is protection and absorption 11.Difference between root hair and stem hair Ans: Root hair Stem hair 1.present in the root Present in the epidermis 2. Always unicellular Cellular or multi Cellular 3. These are temporary These are not temporary 4. Only present in the root hair region of root Present all over the stem 5. Water absorption is a function of root hair Protection and transpiration is the function of stem hair 12.What is meant by free lateral vascular bundle. The xylem and phloem, which are located side by side in the same cell, contain the dividing tissue called the cambium, called the free collateral vascular bundle. Example: Vascular bundles of stems of all angiosperms and dicotyledonous plants where the cambium is located between the xylem and phloem, such as: sunflower, hemoptysis, etc. 13. What does it mean by hadrocentric vascular bundle? The vascular bundle that is located at the center of the xylem and completely surrounded by the phloem is called the hadrocentric or xylem-centric or amphivelas vascular bundle. Example: In the stems of teridophyte or fern plants (eg -pteris, lycopodium, psilotum, selaginella etc), vascular bundles of flowers and fruits of some dicotyledonous plants where the xylem is located in the center and the phloem surrounds the xylem. 14. What do you mean by interstitial region? Answer: The area from the root and pericycle of the stem to the cente is called the interstitial region, i.e. the entire inner part of the stele is called the interstitial region. There are 4 types of tissues in this region. Such asi) Pericycle or wheel ii) Vascular bundle or transport tissue cluster iii) Medullary ray or connective tissue iv) Pith or medulla 15. What do you mean by rib meristematic tissue? Ans: The cells of the dividing tissue which are divided on one floor, so that the cells are lined up in a linear arrangement and look like ribs of the chest, is called rib meristematic tissue. The division of rib dividing tissue results in the formation of a series of cells. Example- Growing roots and marrow of stems are formed from ray rib dividing tissue. 16. Explain the reason why Pteris's transport tissue is called hydrocentric? Ans: The centralized vascular bundle in which xylem is located at the center and phloem completely surrounds it is called hydrocentric or xylem centric or amphibious vascular bundle. In the transport tissue of Pteris or vascular bundle this type of arrangement is seen meaning xylem is at the center and Phloem surrounding the xylem. That is why transport tissue of Pteris is known as hydrocentric. 17. What do you mean by secondary meristematic tissue? Ans: The meristematic tissue which originates from a permanent tissue is called secondary or secondary meristematic tissue. This type of tissue is formed much later in the embryo. From this tissue secondary permanent tissues are produced. As a result the lateral growth of plants occur. They also help protect and heal wounds. Examples- cork cambium, inter fascicular cambium etc.
