Plant Tissues PDF

CLASS 7 PLANT AND ANIMAL TISSUES Cell is the structural and functional unit of life. Cells organise to form tissues. Tissues organise to form organs and organs form organ system Tissues are a group of cells, which are similar in structure and perform a particular function....

CLASS 7 PLANT AND ANIMAL TISSUES Cell is the structural and functional unit of life. Cells organise to form tissues. Tissues organise to form organs and organs form organ system Tissues are a group of cells, which are similar in structure and perform a particular function. Section of skin Section of leaf  Cellular organisation: Plants 1) What is the relationship between leaf cells and leaf? Ans. Tissue and organ 2) What is the relationship between phloem and stem? Ans. Tissue and organ 3) What is the relationship between xylem and plant body? Ans. Tissue and organism 4) What is the relationship between root hair and xylem? Ans. Cell and tissue 5) What is the relationship between protective cells and leaf? Ans. Tissue and organ  Cellular organisation: Animals 1) What is the relationship between skin cells and legs? Ans. Tissue and organ 2) What is the relationship between the brain and animal? Ans. Organ and organism 3) What is the relationship between blood vessel lining and RBC? Ans. Tissue and cell 4) What is the relationship between neuron and the brain? Ans. Cell and organ 5) What is the relationship between muscles and hands? Ans. Tissue and organ  TISSUES Plant Animal Tissues Tissues Meristematic Permanent Tissues Tissues Protective Supportive Conducting / Tissues Tissues complex Tissues Parenchyma Xylem Collenchyma Phloem Sclerenchyma Growth Protective tissue Protection Collenchyma tissue Flexibility Sclerenchyma tissue Support Strength  Meristematic Tissues ▪ Meristems are made up of actively dividing cells. ▪ They are found at all growing points in a plant, like the tips of roots, stems and branches. Characteristics: The cells are small and the cell-walls are thin. The nuclei are large and conspicuous. The cells are almost without vacuoles. The cells actively divide to add new cells. Function: Meristems are actively dividing tissues of the plant. They are responsible for primary (elongation) and secondary growth (thickness) of plant. Types of meristematic tissues based on their location in the plant body 1.Apical meristem : Present in root and shoot tip. It divides in different planes and helps to increase in length. 2.Intercalary meristem: Located at the base of internode or leaf. It helps in elongation of plant body. 3.Lateral meristem: Present on lateral side of the plant body. It helps to increase the thickness or girth of the plant.  Permanent Tissues A permanent tissue is a group of cells in which growth has either stopped completely or for the time being. These tissues form the bulk of the plant body. They do not divide and remain the same throughout the life. According to their function, the types of permanent tissues are : i. Protective tissue ii. Supportive tissue iii. Conducting issue i. Protective Tissue: are found on the surface of root, stems and leaves. The cells have thick walls. Example : Epidermis of leaves. ii. Supporting Tissue : a. Parenchyma: These are living cells, found in the soft parts of the plant. They are composed of large thin-walled cells with intercellular spaces. They store food material(e.g starch in potatoes) and also provide temporary support to the plant. Some parenchyma cells contain chlorophyll. a. i b. Collenchyma : are found in the leaf stalks and below the epidermis of stems. These cells are elongated and are thick at the corners. It helps to support the plant parts. c. Sclerenchyma : These are dead cells, found in stems and veins of the leaves. They are composed of long, narrow and thick cells. This tissue provides strength to the plant parts.  iii. Complex Permanent Tissues /Conducting Tissues / Vascular Tissues : Xylem and Phloem are the two types of conducting tissues. Xylem: Formed of thick-walled, tubular and often dead cells. Xylem tissue consists of tracheids, vessels, xylem parenchyma and xylem fibres. Function: Transports water and minerals absorbed by the roots from the soil, upward to the leaves. Phloem: Formed of living tubular cells. Phloem tissue consists of sieve tubes, companion cells, phloem parenchyma and phloem fibres. Function: Provides a passage for the downward and upward movement of the food, manufactured in the leaves to various parts of the plant. Cellular organisation: IN PLANTS AND ANIMALS 1) Group of cells form what? Ans. Tissue 2) Group of tissues form what? Ans. Organ 3) Group of organs form what? Ans. Organ system 4) Different organ systems together form what? Ans. Organism REVISION – Plant tissue 1) Which tissue in the plant body divides throughout its life? Ans. Meristematic 2) Group of xylem tracheids will form what? Ans. Tissue 3) How is plant protected from external factors? Ans. Protective tissue/epidermal 4) Which tissue helps in storage of food? Ans. Parenchyma 5) Where is sclerenchyma tissue found? Ans. Stem and veins REVISION – Plant tissue 6) The tips of shoot grow fast because of which tissue? Ans. Meristematic 7) Which tissue is present in hemp and linen? Ans. Sclerenchyma tissue 8) Which tissue gives flexibility to the plants? Ans. Collenchyma tissue 9) What is the relation between? Ans. 5) Where is sclerenchyma tissue found? Ans. Stem and veins REVISION – Animal tissue 1) Which tissue helps in body movements? Ans. Muscle tissue 2) Which tissue forms protective membranes? Ans. Epithelial tissue 3) Which tissue helps in connection and binding? Ans. Connective tissue 4) Which tissue helps in transmitting impulses / messages in the body? Ans. Nervous tissue 5) Where is smooth muscle located? Ans. Food pipe, intestinal tract, urinary bladder, blood vessels, iris of eyes