Class 9 Science Important Questions and Answers: Tissues in Action
Plant tissues, animal tissues, musculoskeletal system, skeletal system and types of joints for NCERT, CBSE board exams, Exemplar and Olympiad-level preparation.
Introduction
Tissues are groups of similar cells that work together to perform a specific function. In plants, tissues help in growth, support, transport and protection. In animals, tissues help in movement, coordination, protection, support and transport. This chapter also connects tissues with the musculoskeletal system, bones, muscles, joints and movement.
Chapter Overview
Plant Tissues
Meristematic tissues help in growth, while permanent tissues perform functions like storage, support, photosynthesis and transport.
Animal Tissues
Epithelial, connective, muscular and nervous tissues perform protection, support, movement and coordination.
Musculoskeletal System
Bones, muscles, cartilage, ligaments, tendons and joints work together to produce movement and support the body.
Skeletal System and Joints
The skeleton gives shape, protects organs, helps movement and forms blood cells. Joints allow different types of movement.
Important Keywords
Important Very Short Answer Questions
Q1. What is a tissue?
Answer: A tissue is a group of similar cells that have a common origin and perform a specific function.
Q2. Name the two main types of plant tissues.
Answer: The two main types of plant tissues are meristematic tissue and permanent tissue.
Q3. What is meristematic tissue?
Answer: Meristematic tissue is made of actively dividing cells and is responsible for growth in plants.
Q4. Where is apical meristem found?
Answer: Apical meristem is found at the tips of roots and shoots. It helps in increasing the length of the plant.
Q5. Name the tissue that transports water in plants.
Answer: Xylem transports water and minerals from roots to other parts of the plant.
Q6. Name the tissue that transports food in plants.
Answer: Phloem transports prepared food from leaves to different parts of the plant.
Q7. What is the function of epithelial tissue?
Answer: Epithelial tissue covers body surfaces, protects organs and forms the lining of cavities and ducts.
Q8. Which tissue connects muscle to bone?
Answer: Tendon connects muscle to bone.
Q9. Which tissue connects bone to bone?
Answer: Ligament connects bone to bone.
Q10. What is the basic unit of nervous tissue?
Answer: The neuron or nerve cell is the basic unit of nervous tissue.
Q11. What is a joint?
Answer: A joint is the place where two or more bones meet.
Q12. Name one movable joint.
Answer: The hinge joint in the elbow is a movable joint.
Short Answer Questions
Q1. Differentiate between meristematic tissue and permanent tissue.
Answer:
| Meristematic Tissue | Permanent Tissue |
|---|---|
| Cells divide actively. | Cells usually do not divide. |
| Cells are small, thin-walled and have dense cytoplasm. | Cells are larger and may be living or dead. |
| Responsible for plant growth. | Responsible for support, storage, protection and transport. |
| Found in growing regions of plants. | Found in mature parts of plants. |
Q2. Write the functions of parenchyma.
Answer: Functions of parenchyma are:
- It stores food and water.
- It helps in photosynthesis when chlorophyll is present.
- It provides support in herbaceous plants.
- In aquatic plants, aerenchyma helps in floating.
Q3. Why is sclerenchyma called a mechanical tissue?
Answer: Sclerenchyma is called a mechanical tissue because its cells have thick lignified walls. It provides strength, hardness and support to plant parts such as coconut husk, seed coat and stems.
Q4. What are complex permanent tissues? Give examples.
Answer: Complex permanent tissues are made of more than one type of cell that work together to perform a common function. Xylem and phloem are examples of complex permanent tissues.
Q5. Mention the four types of animal tissues.
Answer: The four main types of animal tissues are:
- Epithelial tissue
- Connective tissue
- Muscular tissue
- Nervous tissue
Q6. Why is blood called a connective tissue?
Answer: Blood is called a connective tissue because it connects different parts of the body by transporting oxygen, nutrients, hormones, carbon dioxide and waste materials. It has cells suspended in a fluid matrix called plasma.
Q7. Differentiate between tendon and ligament.
Answer:
| Tendon | Ligament |
|---|---|
| Connects muscle to bone. | Connects bone to bone. |
| Strong and less elastic. | Strong and elastic. |
| Helps in movement by pulling bones. | Stabilises joints and holds bones together. |
Q8. What is the musculoskeletal system?
Answer: The musculoskeletal system is the body system made up of bones, muscles, cartilage, tendons, ligaments and joints. It provides support, protects organs and helps in movement.
Q9. State the functions of the skeletal system.
Answer: The skeletal system performs the following functions:
- Gives shape and support to the body.
- Protects internal organs.
- Helps in movement with the help of muscles.
- Stores minerals like calcium and phosphorus.
- Produces blood cells in bone marrow.
Q10. Name different types of joints with examples.
Answer:
- Fixed joint: Skull bones
- Hinge joint: Elbow and knee
- Ball and socket joint: Shoulder and hip
- Pivot joint: Joint between skull and first two vertebrae
- Gliding joint: Wrist and ankle
Long Answer Questions
Q1. Explain the types of simple permanent tissues in plants.
Answer: Simple permanent tissues are made of only one type of cell. They are of three main types:
- Parenchyma: It consists of living cells with thin cell walls. It stores food and water. When it contains chlorophyll, it helps in photosynthesis.
- Collenchyma: It consists of living cells with irregularly thickened corners. It provides flexibility and mechanical support to young stems and leaf stalks.
- Sclerenchyma: It consists of dead cells with thick lignified walls. It provides strength and rigidity to plant parts.
Q2. Describe xylem and phloem with their functions.
Answer: Xylem and phloem are complex permanent tissues.
- Xylem: It transports water and minerals from roots to leaves and other parts of the plant. It also provides mechanical support. Xylem includes tracheids, vessels, xylem parenchyma and xylem fibres.
- Phloem: It transports food prepared by leaves to different parts of the plant. This process is called translocation. Phloem includes sieve tubes, companion cells, phloem parenchyma and phloem fibres.
Q3. Explain the four main types of animal tissues.
Answer: The four main types of animal tissues are:
- Epithelial tissue: It covers the body surface and lines internal organs. It protects the body and helps in absorption, secretion and excretion.
- Connective tissue: It connects and supports different body parts. Examples include blood, bone, cartilage, tendon, ligament and areolar tissue.
- Muscular tissue: It is made of muscle fibres and helps in movement. It may be voluntary or involuntary.
- Nervous tissue: It is made of neurons and helps in receiving and transmitting messages in the body.
Q4. Explain the types of muscular tissue.
Answer: Muscular tissue is of three types:
| Type of Muscle | Features | Location |
|---|---|---|
| Skeletal muscle | Voluntary, striated and attached to bones | Arms, legs, face |
| Smooth muscle | Involuntary and non-striated | Walls of stomach, intestine and blood vessels |
| Cardiac muscle | Involuntary, striated and rhythmic | Heart |
Q5. Explain how bones, muscles and joints work together in movement.
Answer: Movement occurs due to the coordinated action of bones, muscles and joints.
- Bones form a rigid framework and act as levers.
- Joints allow bones to move at specific points.
- Muscles are attached to bones by tendons.
- Muscles work in pairs because they can only pull, not push.
- When one muscle contracts, the opposite muscle relaxes.
- This action pulls bones and produces movement.
Q6. Explain the types of joints in the human body.
Answer: Joints are places where two or more bones meet. They are of different types:
- Fixed joints: These joints do not allow movement. Example: skull bones.
- Hinge joints: These allow movement in one direction like a door. Example: elbow and knee.
- Ball and socket joints: These allow movement in many directions. Example: shoulder and hip.
- Pivot joints: These allow rotational movement. Example: joint between skull and first two vertebrae.
- Gliding joints: These allow sliding movement. Example: wrist and ankle.
Case-Study Based Questions
Case Study 1: Plant Growth
A student observed that a plant increased in height after a few weeks. The tip of the shoot showed active growth. On cutting the tip, the plant’s upward growth slowed down.
Q1. Which tissue is responsible for the increase in height?
Answer: Apical meristem is responsible for the increase in height of the plant.
Q2. Why did upward growth slow down after cutting the tip?
Answer: The shoot tip contains apical meristem. When it was removed, actively dividing cells were also removed, so upward growth slowed down.
Q3. Is apical meristem a permanent tissue?
Answer: No, apical meristem is a meristematic tissue because its cells divide actively.
Case Study 2: Injury During Sports
During a football match, a student twisted his ankle. The doctor said that the ligaments around the joint were stretched. He was advised rest and support.
Q1. What are ligaments?
Answer: Ligaments are connective tissues that connect bone to bone.
Q2. Why are ligaments important at joints?
Answer: Ligaments hold bones together and provide stability to joints while allowing movement.
Q3. Which system is involved in this injury?
Answer: The musculoskeletal system is involved because bones, joints and connective tissues are affected.
Case Study 3: Movement of Arm
When a student bends his arm, the biceps muscle contracts and the triceps muscle relaxes. When he straightens the arm, the triceps contracts and the biceps relaxes.
Q1. Why do muscles work in pairs?
Answer: Muscles work in pairs because they can only pull, not push.
Q2. Which joint is present at the elbow?
Answer: The elbow has a hinge joint.
Q3. Which tissue helps in contraction and relaxation?
Answer: Muscular tissue helps in contraction and relaxation.
Assertion-Reason Questions
Directions: Choose the correct option:
- Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
- Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- Assertion is true, but Reason is false.
- Assertion is false, but Reason is true.
Q1. Assertion: Xylem helps in the transport of water and minerals. Reason: Xylem contains vessels and tracheids.
Answer: Option 1. Both statements are true, and the reason correctly explains the assertion.
Q2. Assertion: Blood is a connective tissue. Reason: Blood has cells suspended in plasma and transports materials in the body.
Answer: Option 1. Blood connects different body parts by transporting substances.
Q3. Assertion: Tendons connect bone to bone. Reason: Ligaments connect muscle to bone.
Answer: Option 4. Assertion is false and Reason is also incorrectly framed. Correct statement: Tendons connect muscle to bone, while ligaments connect bone to bone.
Q4. Assertion: Cardiac muscles are involuntary muscles. Reason: Cardiac muscles are found in the heart.
Answer: Option 1. Both statements are true, and the reason supports the assertion.
Q5. Assertion: Ball and socket joints allow movement in many directions. Reason: Shoulder and hip joints are examples of ball and socket joints.
Answer: Option 2. Both statements are true, but the reason gives examples and does not explain the structure directly.
Exam Tips
Use NCERT Keywords
Write terms like meristematic tissue, permanent tissue, xylem, phloem, epithelial tissue, connective tissue, tendon and ligament.
Draw Simple Diagrams
Practise diagrams of neuron, muscle tissue, xylem, phloem and types of joints wherever suitable.
Learn Differences
Important comparisons include xylem vs phloem, tendon vs ligament, bone vs cartilage and voluntary vs involuntary muscles.
Write Point-Wise Answers
For 3-mark and 5-mark questions, write answers in points with examples to score better.
Quick Revision Box
- Tissue means a group of similar cells performing a specific function.
- Meristematic tissues help in plant growth.
- Permanent tissues are formed from meristematic tissues after differentiation.
- Xylem transports water and minerals.
- Phloem transports food.
- Epithelial tissue protects and covers body surfaces.
- Connective tissue supports, binds and connects body parts.
- Muscular tissue helps in movement.
- Nervous tissue helps in coordination and control.
- Tendons connect muscles to bones.
- Ligaments connect bones to bones.
- Skeleton supports the body, protects organs and helps in movement.
- Hinge joint allows movement in one direction.
- Ball and socket joint allows movement in many directions.
FAQ Section
Q1. Which topics are most important in Class 9 Tissues?
Answer: Important topics include meristematic tissue, permanent tissue, xylem, phloem, animal tissues, connective tissues, muscles, bones, joints and the musculoskeletal system.
Q2. What is the difference between xylem and phloem?
Answer: Xylem transports water and minerals, while phloem transports food prepared by leaves.
Q3. Why are bones called connective tissue?
Answer: Bones are connective tissue because they support and connect different body parts and have living cells embedded in a hard matrix.
Q4. What is the role of joints in movement?
Answer: Joints allow bones to move at specific points. Different joints allow different types of movement.
Q5. Is cartilage harder than bone?
Answer: No. Cartilage is flexible and softer than bone. Bone is hard and rigid due to its mineral-rich matrix.
Q6. Which tissue helps in body coordination?
Answer: Nervous tissue helps in body coordination by transmitting messages through neurons.
Final Conclusion
The chapter Tissues in Action builds the foundation for understanding how plants grow, transport materials and stay supported, and how animals move, respond and maintain body structure. For CBSE exams, students should focus on definitions, functions, differences, examples and diagrams. A clear understanding of plant tissues, animal tissues, muscles, bones and joints will help in board exams as well as higher-level competitive preparation.
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