202110203-APEX-STUDENT-WORKBOOK-BIOLOGY-G09-PART1

Biology Workbook_9_P_1.pdf 1 18-10-2019 14:05:30 Name: ___________________________________ Section: ________________ Roll No.: _________ School: __________________________________

Table of Contents 1 24 1 CELL ITS STRUCTURE AND FUNCTIONS 46 2 PLANT TISSUES 68 3 ANIMAL TISSUES 83 4 PLASMA MEMBRANE 106 5 DIVERSITY IN LIVING ORGANISMS 135 6 SENSE ORGANS 155 7 ANIMAL BEHAVIOUR 156 PROJECT BASED QUESTIONS ADDENDUM: ADDITIONAL AS-BASED PRACTICE QUESTIONS

1. CELL ITS STRUCTURE AND FUNCTIONS SESSION 1 INTRODUCTION AND TYPICAL CELL 1.1 Mind Map 1.2 Terminology i. Prokaryotic cell – do not contain a true nucleus or any other membrane–bound or- ganelle. ii. Eukaryotic cell – contains a nucleus and other organelles enclosed within mem- branes. iii. Cell membrane or plasma membrane – surrounds the cytoplasm of living cells, physi- cally separating the intracellular components from the outside environment. iv. Selectively permeable –Cell membrane is selectively permeable as it allows only cer- tain molecules or ions to pass through it by means of active or passive transport. v. Cell wall – is a tough, flexible and rigid layer that surrounds the cell membrane and provides the cells with structural support and protection. SESSION 1. INTRODUCTION AND TYPICAL CELL 1

vi. Nucleus – is a cell structure that contains hereditary information, or DNA, and controls cellular growth and reproduction. vii. Cytoplasm –is a jelly–like fluid between the cell membrane and the nucleus, contain- ing the cytosol, organelles, cytoskeleton, and various particles. viii. Nucleoplasm – is a fluid found in the nucleus of eukaryotic cells. ix. Cellular organelles –are membrane–bound specialized subunits within a cell that have specific functions. 1.3 Key Concepts i. All living organisms are made up of cells. Cell is the smallest structural and functional unit of any organism. ii. All cell organelles shown in the typical plant or animal cell may not exist in every cell. In other words a typical structure of animal and plant cells are different. iii. Cell membrane or plasma membrane is a selectively permeable membrane, made up of mainly lipids and proteins. iv. The cell membrane defines the shape and size of the cell, encloses the cytoplasm and protects it from the external environment. v. In plants cell, a cell wall is a flexible porous layer composed of cellulose, gives a definite shape and protects cell from outward pressure. vi. The nucleus regulates and controls all the functions of a cell and determines the characteristics of the organism. vii. The membrane that encloses the nucleus and separates it from contents of cytoplasm is known as nuclear membrane. viii. On the basis of the presence or absence of nucleus, cells are categorized into prokary- otic cells (without organized nucleus) and eukaryotic cells (with organized nucleus). ix. Cytoplasm is the fluid content bounded by the plasma membrane and contains many specialized cell organelles. 1.4 CCoonncceeppttuuaall UUnnddeerrssttaannddiinngg Q1. Differentiate between (a) Plant cell and animal cell, (b) Prokaryotic and Eukaryotic cells. [Refer to TB page 10 Q1] SESSION 1. INTRODUCTION AND TYPICAL CELL 2

A. a. Plant Cell Animal Cell b. 1. It is enclosed by a rigid cell 1. It is enclosed by a wall in addition to plasma thin, flexible plasma membrane. membrane only. 2. Plastids are present. Green 2. Plastids are usually plants exposed to sunlight absent. contain chloroplasts. 3. A single large central vacuole 3. Many small vacuoles is present. are present. 4. Nucleus lies on one side in 4. Nucleus lies in the the peripheral cytoplasm. centre of the cell. Prokaryotic cell Eukaryotic cell 1. Prokaryotic cell is 1. Eukaryotic cell is found in all characteristic of bacteria plant and animal cells. and blue–green algae. 2. Typical nucleus is 2. A well defined nucleus is absent. Genetic material present. is present in the form of nucleoid. 3. Membrane–bound 3. Membrane–bound organelles are absent. organelles like mitochondria, ribosomes, endoplasmic reticulum etc. are present. 4. Cell wall, if present, is 4. Cell wall in plant cell is made made up of mucopeptide up of cellulose. or peptidoglycan. SESSION 1. INTRODUCTION AND TYPICAL CELL 3

Q2. “Cell is the basic unit of life.” Explain the statement. [Refer to TB page 11 Q5] A. i. Cell is the smallest structural and functional unit of an organism. ii. It contains nucleus which regulates and controls the functions of the entire cell. iii. Different cell organelles present such as mitochondria, endoplasmic reticulum, golgi bodies, ribosomes etc. carry out different functions necessary for survival of life. iv. Overall, cell brings about all the structural and functional activities in the body of an organism, so it is called as the basic unit of life. Q3. What would happen to the cell if nucleus is removed? Give two reasons to support your answer. [Refer to TB page 10 Q2] A. i. Nucleus is the most important organelle of a cell and is spherical in shape. It regulates and controls all the functions of a cell. ii. It determines the characteristics of an organism. iii. Nucleus helps in the process of cell division and reproduction as it has chromo- somes which carry genes and help in transfer of characters from parents to off- spring. They are seen during cell division. iv. If nucleus is removed from a cell the transfer of genetic material would be affected and this in turn affects cell division. Even the control over all the activities would be disturbed and the ill effects will be seen in the organism, as the cell can’t function properly. 1.5 Asking Questions and Making Hypothesis Q1. What happens if plasma membrane ruptures or breaks? [Refer to TB page 11 Q7] A. i. Plasma membrane is the outermost layer of an animal cell that separates the cy- toplasm from the external environment. ii. It plays an important role in maintaining the balance between the various sub- stances inside the cell. iii. It also controls the exchange of substances between the cell and the external environment. SESSION 1. INTRODUCTION AND TYPICAL CELL 4

iv. If plasma membrane is ruptured there will be a certain disturbance to all these activities and the cell cannot function properly. Also the contents of the cell will mix up with the surrounding medium. 1.6 Experimentation and Field Investigation Q1. When you are observing the nucleus of cheek cell in laboratory, what precautions do you take? [Refer to TB page 11 Q9] A. While observing the nucleus of cheek cell in laboratory, one should take following precautions: 1.7 Communication Through Drawing and Model Making Q1. Prepare a model of plant cell or animal cell with locally available materials. [Refer to TB page 11 Q11] A. Student’s Activity The models of Plant Cell and Animal Cell should invariably look like the below given structures: Model of a plant cell – Model of an animal cell – 5 SESSION 1. INTRODUCTION AND TYPICAL CELL

Q2. Draw a typical animal cell and label its parts. [Refer to TB page 11 Q13] A. Student’s Activity SESSION 1. INTRODUCTION AND TYPICAL CELL 6

SESSION 2 CELL ORGANELLES 2.1 Mind Map 2.2 Terminology i. Endoplasmic Reticulum –is a network of membranous tubules, continuous with the nuclear membrane which is involved in protein and lipid synthesis. ii. Golgi body –is a complex of vesicles and folded membranes involved in secretion and intracellular transport. iii. Lysosomes – are cellular organelles that contain digestive enzymes that break down waste materials and cellular debris. They also digest excess or worn–out organelles, food particles, and engulfed viruses or bacteria. iv. Mitochondria – are specialized structures in which the biochemical processes of res- piration and energy production occur. SESSION 2. CELL ORGANELLES 7

v. Ribosomes – is a complex molecular machine found within all living cells, that serves as the site of biological protein synthesis. vi. Plastids –are double–membrane bound organelles found in plants’ and algal cells that are the site of manufacture and storage of important chemical compounds used by the cell. vii. Chloroplasts – are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. viii. Vacuole – is a membrane–bound organelle that stores food or other nutrients required by the cell to survive. They can even store waste products to prevent contamination in the remaining cell. ix. Cells in root tip or growing roots –are actively dividing as cell division occurs rapidly in this part of a plant. 2.3 Key Concepts i. The network of membranes which creates passages within the cytoplasm for the transport of substance from one part of the cell to another is known as endoplasmic reticulum. ii. Endoplasmic reticulum may have some granule like structure on their surface which are called ribosomes, such parts are called as rough endoplasmic reticulum. Areas which do not have ribosomes on them are smooth endoplasmic reticulum. iii. Golgi body is also made up of several membranes. These membranes create sac like structure around which many fluid filled vesicles abound. iv. The function of the Golgi body is to pack various substances before they are trans- ported to other parts of the cell. v. Lysosome contain destructive enzymes which destroys the unwanted materials in the cell. Lysosome are also known as the suicidal bags of the cell. vi. Mitochondria are responsible for cellular respiration, a process through which the cell derives its energy to do work. Because of this, mitochondria are also known as power house of the cell. vii. Chloroplast is a type of plastids in green colour which is present only in plants. viii. Vacuoles are large empty spaces which maintain turgor pressure within the cell. SESSION 2. CELL ORGANELLES 8

2.4 Conceptual Understanding Q1. Lysosomes are known as suicidal bags of the cell. Why? [Refer to TB page 10 Q3] A. i. Lysosomes contain destructive enzymes. ii. Normally, these enzymes do not come in contact with the rest of the cell. iii. At extreme conditions, may be during disease, the lysosomes burst and the en- zymes are released in the cell. iv. These enzymes then digest the cell and destroy it. So,they are called the suicidal bags of a cell. Q2. Why do plant cell possess large sized vacuole? [Refer to TB page 10 Q4] A. i. The vacuole in a plant cell is filled with cell sap which has large amount of water. ii. The water in the vacuole creates pressure which rests against the cell wall. iii. This helps the cell in maintaining its rigidity. iv. If the vacuole is small, their fluid holding capacity would be less and the plant would wilt because of no turgidity and rigidity in the cells. 2.5 Asking Questions and Making Hypothesis Q1. What would happen to the life of the cell if there was no Golgi complex? [Refer to TB page 11 Q8] A. i. The membranes of golgi complex create sac–like structures around which many fluid–filled vesicles abound through which proteins produced in ribosomes reach here. ii. The function of the golgi bodies is to package various substances before they are transported to other parts of the cell. iii. From there, the substances are transported to cell membrane where they are used to regenerate and repair membrane. iv. The substances not transported to membrane are sent to lysosomes for digestion. SESSION 2. CELL ORGANELLES 9

If absent in a cell, the functions carried by golgi bodies will not take place thus affecting the functioning of the entire cell. 2.6 Information Skills and Projects Q1. Read the chapter carefully. Collect the information about the functions of different cell organelles and make a table containing cell organelles and their function. Do not forget to write your specific findings below the table. [Refer to TB page 11 Q10] A. S. Cell organelle Function No. 1. Nucleus controls and organises all the functions of a cell 2. Endoplasmic involved in protein synthesis and Reticulum transport of proteins to other parts of cell 3. Golgi helps in packaging of various Apparatus substances before they are transported to other parts of the cell 4. Lysosomes releases enzymes to destroy the foreign bodies and pathogens 5. Ribosome involved in protein synthesis 6. Mitochondria site for cellular respiration 7. Plastids– helps in photosynthesis Chloroplast holds water to maintain cell turgidity 8. Vacuole and support the plant i. These cell organelles are present in the cell cytoplasm which is the fluid–content bounded by plasma membrane. SESSION 2. CELL ORGANELLES 10

ii. The entire cell is covered by a cell membrane which separates the cytoplasm and other components of the cell from the external environment, thus protecting the cell. 2.7 Communication Through Drawing and Model Making Q1. Prepare a temporary mount of any leaf peel, observe the stomata and draw their pic- tures? Write a brief note on the same. [Refer to TB page 11 Q12] A. Observation: i. Stomata possesses a small pore called stoma through which exchange of gases takes place, and two guard cells enclosing the stoma. ii. No organelles are present in the stoma, however, the guard cells possess all the organ- elles present in a typical plant cell. iii. In the mount prepared, we were able to observe cell wall, cell membrane, cytoplasm, nucleus and chloroplasts. SESSION 2. CELL ORGANELLES 11

Q2. Look at the following cartoon of a cell. Find out the functions of cell organelles. [Refer to TB page 11 Q14] A. This cartoon of a garment industry represents a cell. The different members of the in- dustry resemble different cell organelles in the following manner: i. Watchman acts as the plasma membrane which allows entry and exit of selective materials only. ii. Power house is similar to mitochondria which looks after the energy production for the cell through respiration. iii. Assembly line represents the ribosomes and RNA involved in protein synthesis. iv. Manager represents the nucleus controlling and regulating the functioning of the entire cell. v. The employees carrying raw material through the office to other sections of the office are working similar to endoplasmic reticulum which help in transport of materials from one part to other parts of the cell. vi. Store or warehouse is compared to storage cells or vacuoles which contains fluid which may contain nutrients, waste products or water. vii. Garbage removal bins represent lysosomes which destroys the foreign material or pathogens from the cell. viii. The entire office space is comparable to cytoplasm in which all other components of the cell are embedded. SESSION 2. CELL ORGANELLES 12

SESSION 3 STRUCTURE AND ORIGIN OF CELLS 3.1 Mind Map 3.2 Terminology i. Cell Theory – is a scientific theory which describes the properties of cells which are the basic unit of structure and reproduction in all organisms. ii. Schleiden and Schwann –Schleiden was a botanist and Schwann was a zoologist who independently proposed the cell theory. iii. Origin of cell –Cells arise from pre–existing cells. 3.3 Key Concepts i. Cells appear flat and two–dimensional in structure, but are three–dimensional in structure. ii. Cell theory was proposed by Schleiden and Schwann, and modified by Rudolf Vir- chow. iii. The two cardinal principles on which the cell theory is based are: a. All living plants and animals are made up of cells and their products. b. All cells arise from pre–existing cells. SESSION 3. STRUCTURE AND ORIGIN OF CELLS 13

3.4 Appreciation and Aesthetic Sense, Values Q1. How do you appreciate the organization of cell in the living body? [Refer to TB page 11 Q15] A. i. Cell is the basic structural and functional unit of a living body. ii. It is composed of organelles which can perform different functions. iii. A cell is self–sufficient as the organelles can carry out functions like respiration, photosynthesis (nutrition), protein synthesis, transport of materials, storage, re- moval of unwanted waste, foreign particles or pathogens (excretion) etc. for sur- vival of the cell. iv. It is amazing to see organisation of group of cells to form tissue, which further give rise to organs, organ systems and complete organism. Q2. If the organization of cell is destroyed due to physical and chemical influence, what will happen? [Refer to TB page 11 Q16] A. i. Cell is the structural and functional unit of any organism. ii. The organelles are organized to fulfil all the necessary functions of the cell and the organism in turn. iii. If the organization in a cell is destroyed due to chemical and physical influence, the activities in a cell will get disturbed. iv. This will, in turn, disturb the functioning of different tissues, organs and organ systems in an organism. Q3. How could you appreciate the function of a tiny cell in a large body of an organism? [Refer to TB page 11 Q17] A. i. Cell may be a tiny part in the large body of an organism, but its proper functioning is very essential for any organism. ii. Different cells perform different functions in an organism. Eg: Muscular cells are responsible for contraction and relaxation of muscles. SESSION 3. STRUCTURE AND ORIGIN OF CELLS 14

iii. Organisation of similar cells in groups form tissues, which in turn, give rise to organs and organ systems, each performing a different function. iv. Therefore, proper functioning of a cell is very essential to make the large body function properly. Q4. Who and when proposed cell theory. When did they prepare it? What are salient features of it? [Refer to TB page 11 Q6] A. i. Cell Theory was first proposed by Schleiden and Schwann around 1838–1839. ii. It was later modified by Rudolf Virchow in 1855 who explained the origin of cells. iii. The two main cardinals of the cell theory are: • All living organisms are composed of cells and products of cells. • All cells arise from pre–existing cells. —— CCE Based Practice Questions —— AS1-Conceptual Understanding Column B Very Short Answer Type Questions a. Stain 1. Match the following. b. Nucleus is absent c. Green part of plants [(Session 1.1)] d. Organised nucleus Column A e. Cell wall i. Red blood cell ii. Chloroplast iii. Eukaryotic cells iv. Plant cell v. Methylene blue CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 15

2. Answer the following questions in one sentence. [Refer to Session 1.1 ] (i) Where are chloroplasts present? (ii) Where is the cell wall present? (iii) Define cell membrane. (iv) What is the function of the nucleus? (v) What is protoplasm? 3. Answer the following questions in one sentence. [Refer to Session 1.2 ] (vi) What is the function of rough endoplasmic reticulum? (vii) Why do we call mitochondria as the ‘power house of the cell’? (viii) Which cells have large number of golgi apparatus? (ix) How does your body acquire energy to perform various activities? (x) What are lysosomes also called as? (xi) What are the folds in the inner mitochondria called? (xii) Name the different types of plastids. (xiii) When cells are observed under a microscope, a network of membranes is seen throughout the cytoplasm. What are they? 4. Answer the following questions in one sentence. [Refer to Session 1.3 ] (xiv) Are cells really flat? CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 16

(xv) How do cells acquire their structure and ability to function? 5. Fill in the blanks. . [Refer to Session 1.3 ] (xvi) All living organisms are composed of cells and (xvii) All cells arise from . Short Answer Type Questions 6. Answer the following questions in 3-4 sentences. (i) [(Session 1.1)] Write any two differences between protoplasm and cytoplasm. Protoplasm Cytoplasm 1. 1. 2. 2. 7. Answer the following questions in 3-4 sentences. (i) [(Session 1.2)] What are mitochondria? (ii) [(Session 1.2)] What are chloroplasts? Long Answer Type Questions 8. Answer the following questions in 6-8 sentences. (i) [(Session 1.2)] Write two functions of each of the following cell organelles: 1. Mitochondria 2. Golgi apparatus 3. Nucleus 4. Endoplasmic reticulum AS2-Asking questions and making hypothesis Short Answer Type Questions 9. Answer the following questions in 3-4 sentences. CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 17

(i) [(Session 1.1)] The cell membrane looks different when observed in water and salt solutions. Is this hypothesis true? Give any two reasons to support your answer. (ii) [(Session 1.1)] What are the precautions to be taken during an experiment to observe a nucleus? 10. Answer the following questions in 3-4 sentences. (i) [(Session 1.2)] There are certain enzymes in the cell which have the ability to destroy the cell; however, they do not destroy. Give reason. (ii) [(Session 1.2)] Your friend has done a temporary mount of a plant cell. What questions will you ask him to know whether he has taken all the precautions while preparing the mount? Long Answer Type Questions 11. Answer the following questions in 6-8 sentences. (i) [(Session 1.1)] The plasma membrane allows only certain substances to enter and exit the cell. What is this special property? What reasons can you suggest for its importance to the cell? 12. Answer the following questions in 6-8 sentences. (i) [(Session 1.2)] Satish says the number of Golgi bodies is more in cells which secrete hormones and enzymes. What questions would you ask him to know the reason for this phenomenon? Write at least four of them. AS3-Experimentation and field investigation Short Answer Type Questions 13. Answer the following questions in 3-4 sentences. (i) [(Session 1.1)] Write a procedure for observing cheek cell. Long Answer Type Questions 14. Answer the following questions in 6-8 sentences. (i) [(Session 1.2)] Write the procedure for observing chloroplast. (ii) [(Session 1.2)] How to observe mitochondria under microscope? AS4-Information skills and projects Short Answer Type Questions CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 18

15. Answer the following questions in 3-4 sentences. (i) [(Session 1.2)] Collect information and write a few points on ‘plastids’. (ii) [(Session 1.2)] What is Golgi complex? What happens if Golgi complex is absent in a cell? Long Answer Type Questions 16. Answer the following questions in 6-8 sentences. (i) [(Session 1.2)] Given below is some information about the properties of a cell. Fill in the gaps. Name of the Shape of the Name of the Function cell cell parts RBC Circular observed disc–like Muscle cell Cytoplasm, nucleus, striations Nerve cell Elongated Carrying messages White blood Cytoplasm, cell nucleus Forming framework, giving shape (ii) [(Session 1.2)] Read the paragraph and answer the questions given below. The endoplasmic reticulum (ER) is a large network of membrane bound tubes and sheets. It is similar in structure to the plasma membrane. ER may have some gran- ule–like structures on their surfaces which are called ribosomes. Such parts are called rough endoplasmic reticulum (RER). Areas that do not have ribosomes on them are CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 19

smooth endoplasmic reticulum (SER). Rough endoplasmic reticulum is site of protein manufacture. The SER helps in the manufacture of fat molecules or lipids important for cell function. The manufactured proteins and lipids are then sent to various places in the cell depending on need, using the ER. Some of these proteins and lipids help in building of the cell membrane. i. Differentiate between rough and smooth endoplasmic reticulum in terms of their structure and function. ii. What are ribosomes? iii. Why are ribosomes important? AS5-Communication through drawing and model making Long Answer Type Questions 17. Answer the following questions in 6-8 sentences. (i) [(Session 1.1)] Draw a neat and labelled diagram of a plant cell. (ii) [(Session 1.1)] Draw diagrams based on the clues given: i. This organelle regulates and controls functions of the cell ii. It has a double membrane iii. It is present in eukaryotic cells 18. Answer the following questions in 6-8 sentences. (i) [(Session 1.2)] Draw a neat and labelled diagram of: i. Mitochondria ii. Chloroplast AS6-Appreciation and aesthetic sense, Values Long Answer Type Questions 19. Answer the following questions in 6-8 sentences. (i) [(Session 1.2)] Imagine what would happen if there are no lysosomes? Appreciate the role of lysosomes. CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 20

20. Answer the following questions in 6-8 sentences. (i) [(Session 1.3)] How do you appreciate the role of cell in a living body? AS7-Application to daily life, concern to bio diversity Long Answer Type Questions 21. Answer the following questions in 6-8 sentences. (i) [(Session 1.3)] Why studying of cell is important? How it is useful for us? Write a note on this. Objective Questions AS1-Conceptual Understanding 22. Choose the correct answer. (i) Cells involved in photosynthesis may contain around chloroplasts. (A) 10–20 (B) 0–7 (C) 5000–6000 (D) 50–200 (ii) Pick the odd one out: (B) Vacuoles (A) Golgi apparatus (D) Plastids (C) Cytoplasm (iii) Camillo Golgi observed Golgi body for the first time in the year . (A) 1898 (B) 1899 (C) 1889 (D) 1886 (iv) are present on rough endoplasmic reticulum. (A) Chloroplasts (B) Plastids (C) Ribosomes (D) Leucoplasts (v) Chloroplasts contain a green pigment called . CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 21

(A) Cell organelles (B) Rhodophyll (C) Leucophyll (D) Chlorophyll (vi) We cannot see the of cells under microscope. (A) colour (B) thickness (C) shape (D) number (vii) This is called the power house of the cell. (A) Cytoplasm (B) Mitochondria (C) Nucleus (D) Plastids (viii) The cell organelle which is only present in a plant cell is (A) Cell wall (B) Cell membrane (C) Nucleus (D) Cytoplasm (ix) This organelle controls all the activities of the cell. (A) Nucleus (B) Cell wall (C) Mitochondria (D) Plasma membrane (x) This organism has a prokaryotic type of cell. (A) Blue green algae (B) Mango plant (C) Fungi (D) Frog (xi) Schleiden called nucleus as (B) Cell’s control room (A) Cytoblast (D)None of these (C) Nucleoid (xii) The fluid present inside the nucleus is known as (A) Nucleoplasm (B) Nuclear fluid (C)Cell fluid (D)Both (A) and (B) (xiii) Which of these organelles are also known as suicidal bags of the cell? CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 22

(A) Golgi bodies (B) Lysosomes (C)Endoplasmic reticulum (D) Ribosomes (xiv) In a cell, this organelle is the site for protein synthesis. (A) Lysosomes (B) Mitochondria (C) Ribosomes (D) Nucleus (xv) In the cell theory, explanation of the formation of new cells was given by (A) Schleiden and Schwann (B) Rudolf Virchow (C)Robert Brown (D)Camillo Golgi (xvi) Coloured plastids are best known as (B) Amyloplasts (A) Leucoplasts (D) Chloroplasts (C) Chromoplasts CHAPTER 1. CELL ITS STRUCTURE AND FUNCTIONS 23

SESSION 1 2. PLANT TISSUES 1.1 Mind Map INTRODUCTION TO TISSUES 1.2 Terminology i. Tissue – is a group of similar cells from the same origin that together carry out a specific function. ii. Cells in onion peel – consist of cell wall, cell membrane, cytoplasm, nucleus and a large vacuole, as present in all other plant cells. iii. Cells in leaf peel –are closely packed and consist of distinct cell walls, nucleus, cyto- plasm, and green–coloured granules called as chloroplasts which are responsible for photosynthesis. Small openings called as stomata are also seen. iv. Cells in root tip or growing roots – are actively dividing as cell division occurs rapidly in this part of a plant. They are responsible for growth in length of the root. 1.3 Key Concepts i. Plants are multicellular organisms performing several life processes such as growth, SESSION 1. INTRODUCTION TO TISSUES 24

respiration, excretion, reproduction, photosynthesis etc. ii. There is specific arrangement of cells in plants to carry out these life processes. iii. Cells with similar structure and functions are present in groups called as tissues. iv. Four basic types of tissues in the plants are: Meristematic tissue, dermal tissue, ground tissue, and vascular tissue. v. Tissues that bring overall growth and repair are called Meristematic tissue vi. Tissues that form outer coverings are called as dermal tissues. vii. Tissues that form the bulk of the plant body, helping in packing other tissues are called as vascular tissues. SESSION 1. INTRODUCTION TO TISSUES 25

SESSION 2 MERISTEMATIC AND DERMAL TISSUES 2.1 Mind Map 2.2 Terminology i. Meristematic tissues – consist of small, densely packed cells or group of cells that have the ability to divide to form new cells. ii. Apical meristem – is the meristematic tissue found at the apices, or tips of the plant, both the tip of the shoot and the root and is a region of actively dividing cells. iii. Lateral meristem –is the meristematic tissue responsible for secondary growth or increase in the girth of the stem in all woody plants and in some herbaceous ones. iv. Intercalary meristem – is the meristematic tissue present at internodes, or stem re- gions between the places at which leaves attach, and leaf bases, especially of certain monocotyledons like grasses. v. Dermal tissue –covers the surface of the plant and protects the inner tissues of the plant from injury and water loss. SESSION 2. MERISTEMATIC AND DERMAL TISSUES 26

vi. Epidermis – is usually a outer protective single layer of cells covering the younger parts of a plant. vii. Mesodermis –is the middle layer of the dermal tissue. viii. Endodermis –is the innermost layer of the dermal tissue. ix. Stomata –are small pores present in the epidermis of the leaf responsible for gaseous exchange and transpiration. x. Guard cells –are two kidney–shaped cells that enclose each stomata. xi. Root hairs –are long hair–like parts present in the cells of roots which increase the surface area of root for absorbing water and nutrients from the soil. xii. Bark –is the several–layered thick dermal tissue formed on the epidermis in big woody trees. 2.3 Key Concepts i. Meristematic tissues are present on the tip sides and in between the layers of other tissues. It is mainly of three types namely –Apical meristem, Lateral meristem and Intercalary meristem/Cambium. ii. Apical meristem is the tissue present at growing tips which brings about growth in length in the plant. iii. Lateral meristem is present at the edges in a lateral disposition and is responsible for growth in girth of stem. iv. Intercalary meristem is present at the areas where branching takes place or flower or leaf stalk grows in the internodes. v. Dermal tissue consists of a single layer of tissue comprising of different types of cells showing variations in terms of their location and function. vi. Dermal tissues are of three main types–Epidermis (outermost covering), Mesodermis (middle layer), and Endodermis (innermost layer). vii. The dermal tissue protects the plants from loss of water, mechanical damage like breaking and cleaning of branches, invasion by parasitic and disease–causing organ- isms. 2.4 Conceptual Understanding Q1. Define the terms: (a) Tissue, (b) Meristematic tissue, and (c) Dermal tissue. [Refer to TB page 21 Q1] SESSION 2. MERISTEMATIC AND DERMAL TISSUES 27

A. (a) Tissue –Group of cells similar in structure and performing a similar function is called a tissue. (b) Meristematic tissue – Tissue that brings about overall growth and repair and consists of continuously dividing cells is called meristematic tissue. (c) Dermal tissue – Tissue that forms the outer covering in a plant and provides protec- tion to the plant body is called as dermal tissue. Q2. Differentiate between the following [Refer to TB page 22 Q2](2)) Apical meristem and Lateral meristem A. Apical Meristem Lateral Meristem 1. It helps in the increase in 1. It gives rise to the length of the plant. growth in girth of the stem in a plant. 2. This tissue is present at the 2. This tissue is present at growing tips. Eg. Root tip, the edges in a lateral Shoot tip. manner. Q3. Diffrentiate between the following [Refer to TB page 22 Q2](6)) Epidermis and Bark A. Epidermis Bark 1. It is the outermost layer covering 1. It is formed above the whole plant. the epidermis in big woody trees. 2. It is composed of a single layer of 2. It forms several cells. layers of cells above the epidermis. 3. Exchange of gases and water 3. It is impervious to takes place through stomata and water and gases. root hair present in epidermis. SESSION 2. MERISTEMATIC AND DERMAL TISSUES 28

Q4. Name the following [Refer to TB page 22 Q3](1)) Growing tissue which causes growth in the length of the plant. A. Apical meristematic tissue causes growth in length of a plant. Q5. Name the following [Refer to TB page 22 Q3](2)) Growing tissue which causes growth in the girth of the plant. A. Lateral meristematic tissue is responsible for bringing about growth in girth of a plant. Q6. Name the following [Refer to TB page 22 Q3](5)) Pores essential for gaseous exchange and transpiration. A. Stomata are the small pores essential for gaseous exchange and transpiration present in leaves of plants. Q7. Compare and contrast the following. [Refer to TB page 22 Q4](2)) Meristematic tissue and Dermal tissue A. Meristematic Tissue Dermal Tissue 1. It brings about overall 1. It forms the outer layer of the growth and repair in a entire plant body and is plant body. protective in nature. 2. It brings about 2. It protects the plant from increase in length, girth water loss, mechanical damage in plants and longitudinal and invasion by pathogens. It growth in monocots also stores excretory products, when present in the accumulated food and internodes or leaf bases. secretory substances. 3. These cells have high 3. Rate of division is lesser as mitosis rate. compared to meristematic tissues. SESSION 2. MERISTEMATIC AND DERMAL TISSUES 29

Q8. Give reasons for the following [Refer to TB page 22 Q5](2)) Epidermis gives protection. A. i. The epidermal cells are brick shaped with no intercellular spaces. ii. Epidermis lines the whole plant body. iii. The cells of epidermis have thicker cell walls which help in protection from parasites and disease causing organisms. iv. Small pores called stomata are seen in the epidermis of the leaf which aid in ex- change of water and gases but protects the plants from excessive loss of water. 2.5 Experimentation and Field Investigation Q1. “Bark cells are impervious to gases and water.” What is the reason? [Refer to TB page 22 Q9] A. i. Several layers of dermal tissue formed above the epidermis of stem of woody trees is called as Bark. ii. The outer layers of the bark are composed of cells with thick layers of lignin and suberin on their cell walls. iii. The presence of suberised cell walls make the bark cells impervious to gases and water, and make them dead. iv. The dead tissues of the bark form a protective barrier from loss of water, mechan- ical damage and invasion of pathogens. 2.6 Information Skills and Projects Q1. Collect information about dermal tissues of plants and in what way they help the plants? [Refer to TB page 22 Q10] A. i. The dermal tissue is present over the entire surface of the plant’s body. ii. The walls of the cells of dermal tissue are comparatively thicker than meristematic tissue. SESSION 2. MERISTEMATIC AND DERMAL TISSUES 30

iii. It protects the plants from loss of water, mechanical damage and invasion by par- asitic and disease causing organisms. iv. In big trees the dermal tissue forms several layers above the epidermis. It is called bark which is impervious to water and gases. v. Stomata and root hair are also dermal tissues that are essential for gaseous ex- change and transpiration as well as absorption of water and minerals respectively. vi. Photosynthesis is also carried out by certain cells of this tissue. vii. Dermal cells also store some secretory substances, excretory products and accu- mulated food in different ways. viii. Gum from trees like Acacia, Neem and Gum tree etc. is also secreted by dermal tissue. SESSION 2. MERISTEMATIC AND DERMAL TISSUES 31

SESSION 3 GROUND AND VASCULAR TISSUES 3.1 Mind Map 3.2 Terminology i. Ground tissue –forms the bulk of the plant body and is useful for storing food and providing physical support to the plant body. ii. Parenchyma –is ground tissue that consists of soft, thin–walled and loosely–packed cells. iii. Collenchyma –is ground tissue that consists of cells thickened at angles and cells are longer as compared to parenchyma. iv. Sclerenchyma –is ground tissue that consists of thick–walled tightly packed cells with- out any spaces. v. Aerenchyma –is the parenchyma tissue which contains large air cavities or spaces. vi. Chlorenchyma –is the parenchyma tissue which contains chloroplasts. vii. Vascular or conducting tissue – is formed of more than one cell type and is responsible for transporting water and nutrients to different parts of a plant. viii. Xylem –is the vascular tissue responsible for the transportation of materials like water and salts from the root. SESSION 3. GROUND AND VASCULAR TISSUES 32

ix. Phloem –is the vascular tissue responsible for transportation of food material pre- pared by photosynthesis to other parts of the plant. x. Vascular bundles –The vascular tissues xylem and phloem together constitute the vascular bundles. xi. Tracheids – are elongated cells in the xylem of vascular plants that help in the trans- port of water and mineral salts. xii. Vessels –are formed by several cells arranged end to end with dissolved cross walls and are much longer than tracheids. They are the main components for water con- duction. xiii. Fibres –are thick–walled sclerenchymatous cells in vascular tissues which provide support and protection to the plant. xiv. Sieve cells –are specialized cells in phloem tissue responsible for transport of sugars, organic nitrogenous compounds and growth of plant. xv. Sieve tubes – are a specialised type of elongated cell in the phloem tissue of flowering plants that are responsible for transporting sugars throughout the plant. xvi. Companion cells –are also called albuminous cells. They fulfill metabolic needs of sieve elements, as they lack nucleus and most organelles at maturity. 3.3 Key Concepts i. Ground tissue forms the bulk of plant body which is useful in storing food and providing physical support to the plant body. ii. There are three types of ground tissue namely –Parenchyma, Collenchyma and Scle- renchyma. iii. The cells of parenchyma are soft, thin walled and loosely packed where as in col- lenchyma tissues are thick walled, longer cells. In sclerenchyma, cells are thick walled and tightly packed without spaces. iv. Vascular tissues are involved in transportation of substances and give mechanical support to the plant. v. Xylem transports water and salts from the roots to different parts of the plant. vi. Phloem conducts transport of food material synthesized in leaves to different parts of the plant. vii. Xylem contains elongated tracheid cells, tubular vessels, fibres and parenchyma. viii. Phloem contains long sieve cells, sieve tubes, companion cells, fibres and parenchyma. SESSION 3. GROUND AND VASCULAR TISSUES 33

3.4 Conceptual Understanding Q1. Differentiate between the following: [Refer to TB page 22 Q2](1), 2(3), 2(4,5)) A. a) Meristematic tissue and Ground tissue SN Meristematic tissue Ground Tissue 1 They are present in They form the bulk of the plant body and help in specific regions and are storing food and providing responsible for overall physical support to the growth and repair of the plant body. plant body. 2 Cells are actively dividing Cells do not divide as with high rate of mitosis. rapidly as meristematic cells. b) Parenchyma and Collenchyma SN Parenchyma Collenchyma 1 Cells in parenchyma are Cells in collenchyma are soft, thin walled and thick walled and longer. loosely packed. 2 They help in They provide support to photosynthesis and store the plant. water and food material. c) Sclerenchyma and Parenchyma SN Sclerenchyma Parenchyma 1. The cells in sclerenchyma The cells in parenchyma are thick walled. are thin walled. 2. The cells are tightly Cells are loosely packed. packed without spaces. SESSION 3. GROUND AND VASCULAR TISSUES 34

d) Xylem and Phloem SN Xylem Phloem 1 Xylem transports water Phloem transports food and salts from the roots to material from leaves to all the parts of the plant. the different parts of the plant body. 2 Xylem contains tracheid Phloem contains sieve cells, tubular vessels, cells, sieve tubes, fibres and parenchyma. companion cells, fibres and parenchyma. Q2. Name the following [Refer to TB page 22 Q3](3), 3(4)) A. a) Large air cavities in the aquatic plants . A: Aerenchyma. b) Storage of food material in parenchyma A: Storage tissue Q3. Compare and contrast between the following. [Refer to TB page 22 Q4](1)) A. Phloem SN Xylem 1. Xylem transports water and salts Phloem transports from the roots to all the parts of food materials the plant. from leaves to all parts of the plant body. 2. Xylem contains tracheid cells, Phloem contains tubular vessels, fibres and sieve cells, sieve parenchyma. tubes, companion cells, fibres and parenchyma. SESSION 3. GROUND AND VASCULAR TISSUES 35

Q4. Give reasons for the following [Refer to TB page 22 Q5](1)) Xylem is a conductive tissue. A. i. Xylem is the vascular tissue that transports water and mineral salts absorbed from the soil to all the plant cells. ii. The cells in the xylem namely tracheids, vessels and fibres help in the transport. iii. The tracheids form tubes that communicate with neighboring tubes through pores, thus helping in conduction. iv. Xylem, is therefore, a conducting tissue. Q5. Though Chlorenchyma, aerenchyma and storage tissues are parenchyma in nature, why do they have different specific names? [Refer to TB page 22 Q6] A. Chlorenchyma, aerenchyma and storage tissue are all parenchyma tissues but are known by different names due to the following reasons: i. Cells in all three tissue types are thin–walled parenchymatous but chlorenchyma tissue is green–coloured containing chloroplasts, aerenchyma has large air cavi- ties, and storage tissue consists of cells filled with food, water or waste products. ii. They all perform different functions –Chlorenchyma helps in photosynthesis; aerenchyma provides buoyancy in aquatic plants and helps them to float; and stor- age tissue serves the function of storage of materials. Thus, due to difference in structural arrangement of cells imparting difference appear- ance to the tissue and different functions, these tissues are known by their specific names. Q6. Describe the functions of –Meristem, Xylem, and Phloem. [Refer to TB page 22 Q7] A. (a) Meristem — It possesses actively dividing cells which bring about overall growth and repair of the plant. (b) Xylem — It helps in conducting water and mineral salts from roots to other parts of the plant. (c) Phloem — It helps in conducting food materials from leaves to all the parts of the plant. SESSION 3. GROUND AND VASCULAR TISSUES 36

3.5 Asking Questions and Making Hypothesis Q1. If you want to know more about tissues in plants what questions are you going to ask? [Refer to TB page 22 Q8] A. I would ask the following questions to know more about tissues in plants: i. What is the role of tissues in a plant? ii. How many different types of tissues are present in a plant? iii. What are the functions that the different types of tissues serve? iv. Are plant tissues similar to animal tissues? v. Do these tissues help a plant to carry out its life processes? 3.6 Communication Through Drawing and Model Making Q1. Draw and label the diagram of T.S of stem. [Refer to TB page 22 Q11] A. SESSION 3. GROUND AND VASCULAR TISSUES 37

T.S. of Stem 3.7 Appreciation and Aesthetic Sense, Values Q1. While observing the internal parts of plants, how do you feel about its structure and functions? [Refer to TB page 22 Q12] A. i. While observing the internal parts of a plant, we really appreciate the structure and function of the different parts. ii. Each tissue in the plant body has a specific arrangement of cells which enables it to perform a specific function suitably. iii. The rapidly dividing cells of meristematic tissue helps in growth and repair, the cell layers of dermal tissue protect the plant, the ground tissue provides for storage and structural support and the cells of vascular tissue are arranged as tubes for conduction of water, mineral salts and food materials throughout the plant body. iv. It is amazing to see how different cells work in coordination to support life pro- cesses of a complete organism. SESSION 3. GROUND AND VASCULAR TISSUES 38

—— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. Answer the following questions in one sentence. [Refer to Session 2.3 ] (i) Name the different types of ground tissues. (ii) What is arenchyma? (iii) Which tissue is responsible for the transport of materials from roots? (iv) Name the tissues which contain chloroplast. (v) What are the tissues involved in transportation of water, salts and food materials across the plant called? (vi) What is phloem? (vii) Name the tissues which provide physical support to plants. 2. Match the following. Column B [(Session 2.2)] a. Dermal layer Column A b. Cambium c. Kidney shaped i. Intercalary meristem d. Transpiration ii. Gum secretion e. Bark iii. Stomata iv. Dermis v. Guard cell CHAPTER 2. PLANT TISSUES 39

3. Fill in the blanks. [Refer to Session 2.2 ] (viii) Meristematic tissues at the growing tip that bring about growth in length are called as . (ix) Tissues present around the edges in a lateral manner and giving rise to growthin girth of the stem are called . (x) We can find the over the entire surface of the body. (xi) Dermal tissue usually consists of layer. (xii) Small pores seen in the epidermis of the leaf are called . 4. Answer the following questions in one sentence. [Refer to Session 2.1 ] (xiii) What are tissues? (xiv) Plants around us are usually multicellular. What life processes do they perform? (xv) Name the basic types of tissues present in plants. (xvi) Make a temporary mount of the onion root on a slide and observe it under a micro- scope. How are the cells in the root arranged? (xvii) Are all the cells of the leaf similar? Short Answer Type Questions 5. Answer the following questions in 3-4 sentences. (i) [(Session 2.2)] Define the terms: i. Xylem ii. Ground tissues CHAPTER 2. PLANT TISSUES 40

(ii) [(Session 2.2)] Differentiate between apical meristem and lateral meristem. 6. Answer the following questions in 3-4 sentences. (i) [(Session 2.1)] What is the effect on the growth of the plants if the roots are cut off? (ii) [(Session 2.1)] How do plants perform life processes? Long Answer Type Questions 7. Answer the following questions in 6-8 sentences. (i) [(Session 2.3)] The vascular tissue in the plants play a very important role. Describe the vascular tissue and its functions. 8. Answer the following questions in 6-8 sentences. (i) [(Session 2.2)] What are the functions of dermal tissue in plants? AS2-Asking questions and making hypothesis Short Answer Type Questions 9. Answer the following questions in 3-4 sentences. (i) [(Session 2.3)] What do you observe if you study a permanent slide of the storage tissue –chlorenchyma under the microscope? Explain in 2 to 3 points. (ii) [(Session 2.3)] If your friend is observing a slide of aerenchyma, what questions should you ask him to understand its structure? AS3-Experimentation and field investigation Short Answer Type Questions 10. Answer the following questions in 3-4 sentences. (i) [(Session 2.3)] You have seen the ground tissue in the T.S of stem. How can you differentiate Collenchyma and Sclerenchyma tissues in the ground tissue? 11. Answer the following questions in 3-4 sentences. (i) [(Session 2.2)] You visited a park and saw the gardener cutting the tips of the plant and watering the stump. What is the significance of both of them to the growth of a plant? 12. Answer the following questions in 3-4 sentences. (i) [(Session 2.1)] Identify the parts of a plant based on their functions as given in the table below: CHAPTER 2. PLANT TISSUES 41

S.No. Function Name of the parts 1. Absorption of water from soil 2. Exchange of gases (air) 3. Photosynthesis 4. Transpiration 5. Reproduction Long Answer Type Questions 13. Answer the following questions in 6-8 sentences. (i) [(Session 2.2)] Describe the activity to find the different types of dermal tissues seen in T.S. of a leaf? 14. Answer the following questions in 6-8 sentences. (i) [(Session 2.1)] Describe an experiment to study the cells in a root tip. Write the pre- cautions you would take. AS4-Information skills and projects Long Answer Type Questions 15. Answer the following questions in 6-8 sentences. (i) [(Session 2.3)] Read the information given below and fill in the relevant missing infor- mation. Name of the Position Function Types tissue Apical, Meristematic Lateral, tissue Intercalary Forms outer Protection most layer of the entire body CHAPTER 2. PLANT TISSUES 42

Ground tissue Forms bulk of Xylem, the plant Phloem Transport of material 16. Answer the following questions in 6-8 sentences. (i) [(Session 2.2)] Small pores seen in the epidermis of the leaves are called stomata. They are enclosed by two kidney–shaped guard cells. Cells of the roots have long hair–like structures called root hairs. They help in absorption of water and salt from the soil. i. What are stomata? How are they protected? ii. What are the hair–like structures on the roots? How are they useful to the plant? 17. Answer the following questions in 6-8 sentences. (i) [(Session 2.1)] List the names of any five unicellular and five multi cellular organisms. Differentiate between the organisms with respect to the following points. • Size and shape • Presence of all cell organelles • Complexity of the body structure AS5-Communication through drawing and model making Short Answer Type Questions 18. Answer the following questions in 3-4 sentences. (i) [(Session 2.3)] Draw a rough diagram of Aerenchyma tissue. 19. Answer the following questions in 3-4 sentences. (i) [(Session 2.2)] CHAPTER 2. PLANT TISSUES 43

Observe the above picture? Which cells are present in this region? Long Answer Type Questions 20. Answer the following questions in 6-8 sentences. (i) [(Session 2.2)] What is the importance of guard cells? Draw diagram of guard cell. AS6-Appreciation and aesthetic sense, Values Long Answer Type Questions 21. Answer the following questions in 6-8 sentences. (i) [(Session 2.3)] Plants need to be taken care of and nurtured to grow beautifully. How would you like to take care of plants? Objective Questions AS1-Conceptual Understanding 22. Choose the correct answer. (i) The cells of are not similar (A) onion peel (B) leaf peel (C)both (A) and (B) (D)none of the above (ii) Name the tissues which bring about overall growth and repair. (A) Ground tissue (B) Vascular tissue (C)Dermal tissue (D)Meristematic tissue (iii) This tissue is also called as cambium (B) Dermal (A) Intercalary meristematic (D) Vascular (C) Stem (iv) This is a type of storage tissue. (B) Apical meristem (A) Parenchyma CHAPTER 2. PLANT TISSUES 44

(C) Aerenchyma (D) Chlorenchyma (v) Name the tissue which covers the plant body and gives protection. (A) Dermal tissue (B) Storage tissue (C)Meristematic tissue (D)Ground tissue (vi) It is responsible for transportation of water and salt. (A) Phloem (B) Xylem (C) Meristem (D) Sclerenchyma (vii) These are the small pores in the epidermis of the leaf. (A) Root hair (B) Stomata (C) Xylem (D) Phloem (viii) Which type of tissue is parenchyma? (B) Meristematic tissue (A) Storage tissue (D)Dermal tissue (C)Ground tissue (ix) This tissue contains large air cavities. (B) Sclerenchyma (A) Aerenchyma (D) Chlorenchyma (C) Parenchyma (x) This tissue is present only in green plants. (A) Chlorenchyma (B) Aerenchyma (C) Parenchyma (D) Collenchyma (xi) Companion cells in the phloem of vascular plants are found in close association with which of the following cells? (A) Sieve cells (B) Sieve tubes (C)Phloem parenchyma (D)Phloem fibres CHAPTER 2. PLANT TISSUES 45

SESSION 1 3. ANIMAL TISSUES 1.1 Mind Map INTRODUCTION TO ANIMAL TISSUES 1.2 Terminology i. Epithelial Tissue –is made up of closely packed cells arranged in one or more layers which line the cavities and surfaces of blood vessels and organs throughout the body. ii. Connective Tissue – is the biological tissue that supports, connects, or separates dif- ferent types of tissues and organs in the body. iii. Muscular Tissue – is the most abundant tissue in most animals that has the special ability to shorten or contract in order to produce movement of body parts. iv. Nervous Tissue – is made up of specialised nerve cells called neurons and is specialised to conduct impulses to various organs in the body thus bringing response to stimuli. v. Continuous sheath –or myelin sheath is found over nerve fibres as greatly extended and modified plasma membrane responsible for increasing the speed of propagation of impulses. SESSION 1. INTRODUCTION TO ANIMAL TISSUES 46

1.3 Key Concepts i. Like plants, animals also carry out different life processes which are carried out by various organ systems. ii. These organ systems are composed of organs which, in turn are made up of tissues. iii. A tissue is a group of cells having similar structure and function. iv. There are four major types of tissues in animals –epithelial tissue, connective tissue, muscular tissue and nerve tissue. v. Epithelial tissue is a covering or protecting tissue, inside or outside the animal body. vi. A loosely spaced tissue mainly carrying different materials to different parts of the body as well as rendering support is the connective tissue. vii. Muscular tissue is responsible for the movements in our body. viii. Nervous tissue is a specialized tissue that responds to internal, external stimuli. 1.4 Conceptual Understanding Q1. What do you understand by the term tissue? [Refer to TB page 37 Q1] A. i. Tissue is the group of cells that are similar in structure and perform similar function. ii. Epithelial tissue, connective tissue, muscle tissue, nerve tissue are the four main types of tissues present in our body. SESSION 1. INTRODUCTION TO ANIMAL TISSUES 47

SESSION 2 EPITHELIAL AND CONNECTIVE TISSUE 2.1 Mind Map SESSION 2. EPITHELIAL AND CONNECTIVE TISSUE 48