Tissue Class 9 NCERT Solutions – The NCERT Solutions for Class 9 Science help students prepare effectively for their examinations by providing them with a comprehensive set of solutions. These solutions serve as a vital resource for students who may find it difficult to locate the answers to the questions on their own. Students can use these solutions to build a solid foundation in Science and achieve academic success.
Tissue Class 9 NCERT Solutions
Q. What is a tissue?
Answer – A tissue is a group of similar cells that work together to perform a specific function in a living organism.
Q. How are tissues used by multicellular organisms?
Answer – Tissues in multicellular organisms serve two main purposes:
Firstly, they provide structural and mechanical support to the organism. Different types of tissues such as connective tissues, bone tissues and vascular tissues, help maintain the shape, form and integrity of the organism.
Secondly, tissues enable division of labour among different cells in the organism, by allowing specialized functions to be carried out. For example, muscle tissue allows for movement, while nervous tissue allows for communication and coordination of different bodily functions. This specialization of cells allows for more complex and efficient functioning of the organism.
Q. Name the types of simple tissues.
Answer – Plant: Parenchyma, Collenchyma, Sclerenchyma
Q. Where is apical meristem found?
Answer – The apical meristem is located at the tips of the roots and shoots in plants, and it is responsible for the growth of the plant in length and height, respectively.
Q. Which tissue makes up a coconut’s husk?
Answer – The husk of a coconut is made up of a strong and tough tissue called sclerenchyma. It gives support and protection to the fruit, and makes it stiff and hard. Sclerenchyma contains dead cells with thick, durable walls that have lignin to make them strong.
Q. What are the constituents of phloem?
Answer – Phloem is a complex tissue found in vascular plants that is responsible for the transport of food materials, such as sugars and amino acids, from the leaves and other sources of the plant to the different parts of the plant where they are needed. There are four primary cell types found in phloem tissue:
- Sieve tube elements: These are long, slender cells that form a continuous tube through which food materials are transported.
- Companion cells: These are smaller cells that are closely associated with sieve tube elements and play a role in controlling their activities.
- Phloem fibers: These are long, narrow cells that provide mechanical support to the phloem tissue.
- Phloem parenchyma: These are relatively unspecialized cells that are involved in storage and other metabolic functions within the phloem tissue.
Q. Which body part’s movement is caused by which tissue?
Answer – Movement in our body is achieved through the coordination of two types of tissues: muscular tissue and nervous tissue.
Muscular tissue, consisting of skeletal, smooth, and cardiac muscle, is responsible for generating force and producing movement in response to nervous system signals.
Nervous tissue, on the other hand, is responsible for detecting, processing, and transmitting information in the form of electrical impulses throughout the body. This tissue coordinates and controls the activity of the muscular tissue by initiating and modulating the strength, duration, and timing of muscle contractions to produce smooth and coordinated movement.
Q. What does a neuron look like?
Answer – A neuron is a specialized type of nerve cell that plays a critical role in transmitting information throughout the nervous system. It has a unique shape and structure, consisting of a cell body that contains a nucleus and cytoplasm, and long, thin extensions called axons and shorter, branched extensions called dendrites.
Q. Name three characteristics of the cardiac muscle.
Answer – The heart’s muscles or cardiac muscles are highly specialised organs that circulate blood throughout the body.
- They are shaped like cylinders have striated muscle fibres.
- Cardiac muscles are uninucleated and branched, in contrast to skeletal muscles, which have numerous nuclei.
- These muscles cannot be actively controlled by the person because they are involuntary in nature. Instead, the cardiac conduction system—a network of specialised cells that manages the heart’s contractions—controls them.
Q. What purposes does areolar tissue serve?
Answer – Areolar tissues, which are a type of loose connective tissue, are commonly found in animals and serve a variety of functions. They can be found in the spaces between the skin and muscles, as well as around blood vessels and nerves throughout the body. They are also present in bone marrow and can be found inside organs, where they provide support and assist in tissue repair. Areolar tissues play a crucial role in maintaining the overall structure and integrity of the body, helping to connect and bind different tissues and organs together. They also play a role in immune defense, nutrient and waste exchange, and edema control.
Q. Define the term ’tissue’.
Answer – A collection of cells that share a common structure and cooperate to carry out a particular job in the body is referred to as a tissue. Cells that are designed to carry out a specific function make up tissues, and these cells cooperate to complete tasks.
Q. What combination of different elements makes up the xylem tissue? Name them.
Answer – Transporting water and nutrients from the roots to the rest of the plant is the job of the specialised plant tissue known as xylem. It is made up of four major components, including:
- Vessels: These are lengthy, tube-like structures that are produced by the fusion of separate cells and serve as a continuous conduit for the transportation of water.
- Tracheids: Water can pass through tiny openings in the cell walls of these long, slender cells called tracheids, which have tapered ends.
- Xylem fibres: These elongated, cells with thick walls sustain the plant mechanically.
- Xylem parenchyma: These cells perform a variety of support functions, including respiration, storage, and other functions.
Q. How you will differentiate simple tissues in plants from complex tissues?
|Simple Tissues||Complex Tissues|
|Made up of only one type of cell.||Made up of more than one type of cell.|
|Have a single function in the plant.||Have multiple functions in the plant.|
|Examples include parenchyma, collenchyma, and sclerenchyma.||Examples include xylem and phloem.|
|Usually located in the outer regions of the plant.||Typically found in the inner regions of the plant.|
|Provide structural support and protection to the plant.||Facilitate the transport of water, nutrients, and other substances throughout the plant.|
Q. Determine the differences in cell walls between parenchyma, collenchyma, and sclerenchyma.
|Tissue||Cell Wall Thickness||Composition||Function|
|Parenchyma||Thin||Primary cell wall containing cellulose and pectin||Storage, photosynthesis, gas exchange|
|Collenchyma||Thickened at corners||Primary cell wall containing cellulose, hemicellulose, and pectin, with some lignin deposition||Support for growing organs|
|Sclerenchyma||Very thick and lignified||Secondary cell wall containing cellulose, hemicellulose, lignin, and sometimes suberin||Support, protection, and strength|
Q. What are the stomata’s purposes?
Answer – Stomata are small openings or pores found on the epidermis of plant leaves, stems, and other organs. They allow for the exchange of gases such as carbon dioxide and oxygen, which is essential for photosynthesis. Stomata also play a role in transpiration, which involves the loss of water vapor from the plant through the stomatal pores.
Q. Diagrammatically depict the variations between the three categories of muscle fibres.
Answer – There are three different types of muscle fibers –
- Striated muscles Fibers:
- Appear striated or striped under a microscope
- Have multiple nuclei
- Are cylindrical in shape
- Can be voluntarily controlled
- Attached to bones by tendons
- Generate rapid and powerful contractions
- Smooth Muscle Fibers:
- Appear smooth and non-striated under a microscope
- Have a single nucleus
- Are spindle-shaped
- Are not under voluntary control
- located in the blood vessels and stomach, among other internal organs, walls.
- Generate slow and sustained contractions
- Cardiac Muscle Fibers:
- Appear striated under a microscope
- Have a single nucleus
- Are branched in shape
- Are not under voluntary control
- Found only in the heart
- Generate strong and rhythmic contractions
Q. What job does the cardiac muscle perform?
Answer – Cardiac muscles are specialized muscle tissues found only in the heart. They are characterized by their unique features, which include:
- Branched and cylindrical shape
- Uninucleated cells
- Involuntary control
- Striated appearance under a microscope
- Generate strong and rhythmic contractions
- Responsible for pumping blood throughout the body
- Have the ability to contract and relax rhythmically throughout one’s lifetime
- Capable of sustaining activity for long periods without fatigue
Q. Based on their structure and position in the body, differentiate between striated, un-striated, and cardiac muscles.
|Striated muscles||Long cylindrical fibers with visible striations||Skeletal muscles attached to bones||Voluntary control||Movement of bones and body|
|Smooth muscles||Spindle-shaped fibers without visible striations||Internal organs, blood vessels, and glands||Involuntary control||Control of internal organ function (e.g. digestion, blood flow)|
|Cardiac muscles||Branched, cylindrical fibers with visible striations||Heart||Involuntary control||Pumping of blood throughout the body|
Q. Draw a labelled diagram of a neuron.
Q. Name the following.
(A) The tissue that lines the inside of our mouths.
(b) In humans, the connective tissue between muscle and bone.
(c) Plants’ food-transporting tissue.
(d) Body tissue that stores fat.
(e) Tissue that is connected by a fluid matrix.
(f) Brain tissue is found.
(a) Stratified squamous epithelium
(d) Adipose tissue
(f) Nervous tissue
Q. Identify the type of tissue in the following:
Skin, lining of kidney tubule, bark of tree, bone, vascular bundle.
- Skin – Stratified squamous epithelial tissue
- Bark of tree – Cork cambium (a type of meristematic tissue)
- Bone – Osseous tissue (a type of connective tissue)
- Lining of kidney tubule – Simple cuboidal epithelial tissue
- Vascular bundle – Complex tissue (contains both xylem and phloem)
Q. Identify the areas that have parenchyma tissue.
Answer – Parenchyma tissue is present in various regions of plants including:
- Cortex and pith of stems and roots
- Mesophyll of leaves
- Fruits and seeds
- Endosperm of seeds
- Resin ducts
- Medulla of stems
- Pericycle and xylem of roots.
Q. What function does the plant epidermis serve?
Answer – The epidermis is the outermost layer of cells in plants, which covers and protects the underlying tissues from mechanical injury, water loss, and invasion by pests and pathogens. It also plays a crucial role in the exchange of gases, regulating water loss through stomata and facilitating the absorption of water and minerals from the soil. Additionally, the epidermis can secrete waxy substances to reduce water loss and to prevent harmful substances from entering the plant.
Q. How does the cork function act as a barrier?
Answer – Cork tissue forms a protective layer in plants due to its dense arrangement of dead cells with no intercellular spaces. The walls of the cork cells are impervious to water and gases due to the deposition of suberin.
Q. Complete the following chart.