NCERT Solutions for Class 9 Science Chapter 6 - Tissues
Chapter 6 in the Science book of class 9 is Tissues. Science is an important subject for class 9 and 10 as it forms the base for higher studies if any student wants to pursue a career in Science. The topic which we will cover now is tissues class 9, it holds much importance in the exams. Not only in the exams, but a higher and a bit complex version of this chapter is present in the higher classes if you want to pursue science as a subject. This class 9 science chapter 6 forms the basis of almost all types of topics related to human physiology. We will be able to solve NCERT Solutions class 9 science chapter 6 on our own after reading this chapter. The NCERT solution for class 9 science chapter 6 pdf is available on the website of Vedantu in the study material column. Maths Students who are looking for better solutions, they can download Class 9 Maths NCERT Solutions to help you to revise complete syllabus and score more marks in your examinations.
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NCERT Solutions of Class 9 Science Chapter 6 – Free PDF Download
NCERT Science Class 9 Chapter 6
You can opt for Chapter 6 - Tissues NCERT Solutions for Class 9 Science PDF for Upcoming Exams and also You can Find the Solutions of All the Maths Chapters below.
This NCERT class 9 chapter 6 is of tissues. The cells are the basic structural and functional unit of the body. The cells of the body unite together and then they form the tissues. So tissues are just a group of similar types of cells that have united to perform a function in the body. When more and more tissues join together, they form the organs and more organs join together to form an organ system. These cells by which tissue is made can be structurally similar and dissimilar. This chapter 6 science class 9 along with the NCERT solutions for class 9 science chapter 6 will help us to excel in exams. We will study about two types of tissues in this class 9 science chapter 6. They are plant tissues and animal tissues.
The tissues class 9 chapter has two types of tissues. Firstly, we will study plant tissues. The plant tissues are made up of two different types of tissues. They are meristematic tissue and permanent tissues. We will study both of these tissues below.
There are 2 types of tissues. The first is meristematic tissues.
A group of immature cells that are about to divide or are in the continuous phase of division are known as meristematic tissues. The main functions of these tissues are to provide the growth of the plant. The meristematic tissues are responsible for the primary growth of the plant and its subsequent growth after that. Meristems are the areas in the plant body that possess these meristematic cells. As these areas have meristematic cells so they are the regions of high growth and cell division. The cells that are produced by meristematic cells have lost their capacity to divide. The classification of meristems in the ch 6 science class 9 is based on two types:
On the basis of origin in the life of a plant, they are Primary meristems and secondary meristems.
On the basis of position in the plant body, they are of three types: Apical meristem, Lateral meristem and intercalary meristem.
Primary Meristems: These are the cells that appear in the plant at the time of birth or in their early stages of life. They are the major contributors to the formation of the plant body. The cells of the primary meristems are always in an active state of division. Primary permanent tissues are formed by these cells only.
Secondary Meristems: As their name suggests, these meristems appear after the primary meristems. These appear in the later stages of life and are responsible for the secondary growth of the plant. These meristems help in the growth of secondary tissues and are mainly responsible for forming the woody regions of the plant.
Apical Meristems: Apical is known as the tip. So as the name suggests, these tissues are present at the apices or the tips of the plants. The tips are the roots and tip of the stem. They help in growing the roots and stem. They are responsible for increasing the length of the plant. This increase in the length of the roots and stem is known as primary growth.
Lateral Meristems: These meristems are present on the lateral sides of the roots and stem. They are not present on all the plants. These tissues appear in the later stages of life and are not present in the beginning. The secondary tissues are produced with the help of these tissues. They help the plant to grow laterally.
Intercalary Meristems: These meristems are present in between the mature tissues of the plant. These tissues help in increasing the length of the plant and also of its organs.
These tissues are present in the later stages of life. Those cells of the plants have lost the capacity to divide after primary division and then again they retain their capacity to divide. These newly formed cells form the secondary tissues of the plant. The permanent tissues are of two types are Simple permanent tissue and Complex permanent tissue.
Simple Permanent Tissue: These tissues are made up of only one type of cell. These cells are structurally and functionally similar to one another. Parenchyma, Collenchyma and Sclerenchyma.
Parenchyma: It forms the major component of various plant parts such as roots, stem and leaves. They are known as living cells because these cells do not lose their protoplasm in their growth phase. The cells of parenchyma are of equal diameters. They have thin cell walls and their walls are made up of cellulose. No intercellular spaces are present inside them. They help in the process of photosynthesis, storing of food and also secretion of waste materials.
Collenchyma: They are also living cells. They are elastic in nature and have mechanical tissue. The cells of collenchyma are oval, spherical or polygonal in shape. The cell walls are thick. Cellulose, hemicellulose and pectin are present in its cell wall. They provide strength to the walls.
Sclerenchyma: These are hard tissues and are dead in nature. They help in providing protection to the cells. No protoplast is present inside them therefore they are considered dead in nature. The cell walls are very thick in nature and they have a presence of numerous pits. Lignin and cellulose are deposited in its cell walls. Due to this thickening, the cell walls become impermeable to water.
Complex Permanent Tissue
As the name suggests, these tissues are made up of more than one type of cells. These cells are different from one another in their form and structure. So, the complex tissues are a combination of dissimilar cells that unite together to perform certain functions. Xylem and phloem are the two different types of complex tissues.
Xylem: This tissue is mainly responsible for conducting the water in the plants. As it helps in conducting water and minerals from the roots of the plant to the stem and leaves, it is also known as conducting tissue. It also helps in providing mechanical support and strength to the plant. This helps in tackling the pulling forces and tolerate environmental stresses. The protoxylem is formed first and the metaxylem is formed later on. The vessels in protoxylem have a narrow diameter whereas in metaxylem they have vessels having a broad diameter. When the protoxylem is arranged in the centre and then the metaxylem surrounds it, this condition is known as the endarch type. When the metaxylem is present in the centre and protoxylem surrounds it, this condition is known as the exarch condition. The xylem has four different elements and is Tracheids, Vessels, Xylem fibres and Xylem parenchyma.
Phloem: The phloem is a living tissue. It is responsible for carrying out the food materials in the plant. The food that is prepared in the leaves of the plant is transported to the different parts of the plant with the help of the xylem. In primary phloem, the protophloem is formed first and the metaphloem is formed after that. The secondary phloem is responsible for the secondary growth of the plant. The phloem is also made up of four elements. They are the Phloem Parenchyma, Phloem Fibers, Sieve tube elements and companion cells.
When we study tissues class 9, we get to understand that there are three types of tissue systems that are present in plants. We then need to go through NCERT class 9 science chapter 6 to understand them more clearly so that we can do well in our exams.
Epidermal tissue system
Ground tissue system
Vascular tissue system
Some of the important tissues of these above three tissue systems are:
Epidermis: This is the outer layer of the plant. It is single-layered in some plants and multi-layered in some plants. It serves the purpose of protection to the plant. As it provides a covering to the plant, this tissue does not let the water from the plant evaporate from its barks.
Stomata: This is a system of tissue that helps the plants to respire. Plants take up carbon dioxide and provide oxygen. They make up their food by the process of photosynthesis. These stomata are the pore-like structures that are responsible for the gaseous exchange that takes place in plants. These cells also control the process of transpiration in the plants.
Secondary Growth in Plants
In class 9 science chapter 6 we get an understanding of the secondary growth in plants. The growth of the root and stem is known as primary growth. This growth takes place with the help of apical meristems. The lateral meristems are responsible for the secondary growth of the plant. They help to increase the girth of the root and stem. The lateral meristems are the Intrafascicular cambium, Interfascicular cambium and the cork cambium. These lateral meristems are responsible for the secondary growth of the plant. The vascular bundles get arranged in a ring-like manner. They are arranged around the central pith and are conjoint and open. As they possess cambium therefore they are called open tissues. It is known as intrafascicular cambium. The cells start the process of dedifferentiation and in this way, the cambium function also starts and the cambium rings are formed. These cambium rings that are formed by the cambium start dividing. From the observations, it is seen that the cambium is more active on the inner side as compared to the outer side.
After going through the NCERT solutions for class 9 science chapter 6 tissues and understanding the plant tissues, we will now study the animal tissues.
There are four types of animal tissues. They are:
Epithelial Tissue: These tissues have a basal surface and a free surface. The basal surface is present in contact with the basement membrane. The basement membrane is a non-cellular layer. This basement membrane is responsible for providing elastic support to the connective tissues that are lying under them. The connective tissues obtain nutrients from the basement membrane. These epithelial tissues are present outside the body and also inside of the body to provide protection to the cells of the body. It is of two types: Simple Epithelium and Compound epithelium.
Connective Tissue: In the body of animals, this tissue is most widely distributed and is the most abundant type of tissue. The cells of this tissue are embedded in the intercellular matrix and this helps in connecting them with different tissues. Some type of connective tissue are:
Areolar Tissue: This type of tissue is most widely distributed in the human body. The matrix of this tissue is made up of modified polysaccharides and proteins. It helps in joining the skin to muscles. This tissue is found around the blood vessels, nerves and around muscles. They act as packaging and supporting tissue between the organs of the body cavity. After an injury, they help in repairing up the tissue.
Adipose Tissue: This tissue is an aggregation of fat tissues. These tissues are oval and round in shape and they are completely filled with fat. They are located just below the skin and also around some delicate organs like the heart, kidney and lungs. They help in the fat reservation. As they have fat, they form good cushioning tissues.
Tendon: Tendon tissue is also known as sinew. It is a band of fibrous connective tissues. Tendons join muscles to bones. It is also capable of withstanding tension. Tendon is made up of collagen and thus they are similar to the ligaments. Just one function that differentiates between tendon and ligament is that tendons join muscle to bones whereas ligament connects bone to bone. They are very strong and are thus able to withstand the tension that is generated by muscular contractions. This is because of their parallel orientation and the composition of tissue fibres in the tendon.
Muscular Tissues: The mesoderm is responsible for the generation of muscles. Myocytes are responsible for making up muscle tissue. These cells are bound together by connective tissue and form muscular tissue. A human body has almost 640 muscles. On the basis of location, muscles are classified into three types:
Skeletal Muscle: They are also known as voluntary muscles or striated muscles. They are attached to the skeleton component of the body. They are involved in locomotory actions and are also responsible for body posture. Alternate dark and white bands are visible on them when they are viewed under a microscope, therefore, named striated muscles. They are voluntary muscles thus they are in control of the animals. Example: Muscles of hindlimbs and forelimbs.
Smooth muscle: They are also known as unstriped muscles. Cells in these muscles are elongated and spindle in shape. They don't possess alternate dark and light bands. They give a smooth appearance when they are seen under a microscope. These muscles line the hollow organs and are involuntary in nature thus not in control of animals. Example: Posterior regions of oesophagus and stomach.
Cardiac Muscles: As it is there in their name, these muscles line the heart walls. Alternate light and dark bands appear in these muscles. They are responsible for increasing and decreasing muscular activity.
Nervous tissue: This tissue is responsible for controlling the body’s neural function. Nerve cells are present between them that are the simplest structural and functional cells of the nerve cells. Nerve cells are also called neurons. Neurons are protected by neuroglial cells. Synapse is made up of neurons. it is a portion where the signal is transferred from one part of the neuron to another part.
NCERT Solutions for Class 9 Science Ch 6
After going through the above information about tissues and also going through their solutions, we have thoroughly understood each and every detail of the chapter. As per the experts of Vedantu, this material is prepared for the students. This material is prepared by keeping the examination point of view. The previous year exam papers and the pattern CBSE follows to set up these examination papers have been thoroughly studied and then put into this content by our expert’s panel team. We hope all the students who wish to excel in their examination go through this material as it is easy to read and understand and will surely give you an edge over other students in the examination. When you will see the questions that you have practised here in your exam, you would surely have a morale boost. This will also give you confidence for future examinations. Vedantu helps the students to prepare for all kinds of examinations whether they are board-level examinations or entrance-level examinations. You can go through our study material anytime and from anywhere and study and then excel in the examination. Education is the best gift we can give to anyone and we at Vedantu always focus on the quality of education and our content that it is prepared under expert guidance so that it is easy for students to study and understand and also give them an edge over other students in the examination.
FAQs (Frequently Asked Questions)
1. What are the Two Types of Vascular Bundles Present in Plants?
Answer: The two types of vascular bundles are:
Open Vascular Bundles: In these types of vascular bundles, cambium tissue is present. It is present in between xylem and phloem elements. The bundles are said to be open. These types of bundles due to the presence of cambium, have the ability to form secondary xylem and phloem or in other words, they are capable of secondary growth. As they are open for secondary growth, therefore they are named open vascular bundles. They are present in dicots.
Closed Vascular Bundle: The cambium tissue is absent in these types of vascular bundles. The xylem and phloem tissues are joined together and no cambium is present in them. No secondary growth is seen in these types of vascular bundles. Due to this, they are known as closed vascular bundles as they are closed for secondary growth.
2. What is Cork Cambium?
Answer: The cork cambium is the main tissue that is responsible for the formation of wood. The girth of the stem increases due to increased activity of the vascular cambium. As the girth keeps increasing the outer cortical layers starts rupturing. So, cork cambium produces new layers that replace the damaged or ruptured layers. Cork cambium is also called phellogen. The cork cambium has another name that is stellar cambium. Phellogen is thick and has two layers. The outer one forms the cork and the inner one forms the secondary cortex. The cells of cork are compactly arranged and in the beginning, they have thin cellulose cell walls. When they mature the living part is replaced by the non-living part which is the formation of wood material. The cell walls of the cork become thick by the deposition of suberin.