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Comprehensive Locomotion and Movement Class 11 notes, summary, MCQs, important questions, keywords and exam tips for quick revision.

Introduction of the Chapter

The chapter Locomotion and Movement in Class 11 Biology explains how living organisms move from one place to another and how body parts move internally. Movement is a fundamental property of life. Even microscopic organisms show movement.

In humans, locomotion and movement are possible due to the coordinated action of the muscular system, skeletal system, and nervous system. The chapter covers types of movements, structure of bones and joints, muscle contraction, and common disorders of bones and muscles.

Understanding Locomotion and Movement Class 11 is essential for board exams as well as competitive exams like NEET.

Short Notes (Quick Revision Points)

Movement is the change in position of body parts.
Locomotion is movement of the whole body from one place to another.
Types of movements: Amoeboid, Ciliary, Muscular.
Human skeleton has 206 bones.
Skeleton is divided into axial and appendicular skeleton.
Joints are points where two bones meet.
Muscles are of three types: skeletal, smooth, cardiac.
Sliding filament theory explains muscle contraction.
Actin and myosin are contractile proteins.
Disorders: Arthritis, Osteoporosis, Muscular dystrophy.

Detailed Summary of Locomotion and Movement Class 11 (1000–1200 Words)

The chapter Locomotion and Movement Class 11 describes the mechanisms by which organisms move. Movement is a characteristic feature of all living organisms. It may be voluntary or involuntary.

Types of Movement

Movement can be classified into three main types:

Amoeboid Movement
Ciliary Movement
Muscular Movement

Amoeboid Movement

Amoeboid movement occurs due to the formation of pseudopodia. It is seen in organisms like Amoeba and in human white blood cells. The cytoplasm flows in the direction of movement.

Ciliary Movement

Ciliary movement occurs through cilia. It is seen in the respiratory tract and fallopian tubes. Cilia beat rhythmically to move substances.

Muscular Movement

Muscular movement is the most common type in higher animals. It occurs due to contraction and relaxation of muscles.

Human Skeletal System

The human skeletal system provides support and protection. It also helps in locomotion and movement.

The human skeleton is divided into:

Axial Skeleton

It includes:

Skull
Vertebral column
Ribs
Sternum

It forms the central axis of the body.

Appendicular Skeleton

It includes:

Pectoral girdle
Pelvic girdle
Limbs

It helps in movement and locomotion.

Types of Bones

Long bones (Femur)
Short bones (Carpals)
Flat bones (Skull bones)
Irregular bones (Vertebrae)

Joints

Joints are connections between bones.

Types of joints:

Fibrous Joints

Immovable joints. Example: Skull sutures.

Cartilaginous Joints

Slightly movable joints. Example: Between vertebrae.

Synovial Joints

Freely movable joints.

Types of synovial joints:

Ball and socket joint (Shoulder)
Hinge joint (Elbow)
Pivot joint (Atlas-axis)
Gliding joint
Saddle joint
Condyloid joint

Muscular System

Muscles are specialized tissues responsible for movement.

Three types of muscles:

Skeletal Muscles

Voluntary
Striated
Attached to bones

Smooth Muscles

Involuntary
Non-striated
Found in visceral organs

Cardiac Muscles

Involuntary
Striated
Present in heart

Structure of Skeletal Muscle

Skeletal muscle is composed of muscle fibers. Each muscle fiber contains myofibrils. Myofibrils have repeating units called sarcomeres.

Sarcomere is the functional unit of muscle contraction.

Important bands:

A-band
I-band
Z-line
H-zone
M-line

Sliding Filament Theory

The sliding filament theory explains muscle contraction.

According to this theory:

Actin and myosin filaments slide over each other.
The length of filaments remains constant.
Sarcomere shortens during contraction.
ATP is required for contraction.

This mechanism is very important in Locomotion and Movement Class 11 for exams.

Mechanism of Muscle Contraction

Nerve impulse reaches muscle fiber.
Calcium ions are released.
Cross bridges form between actin and myosin.
Myosin head pulls actin filament.
ATP is used.
Muscle contracts.

Disorders of Muscular and Skeletal System

Arthritis: Inflammation of joints.
Osteoporosis: Decrease in bone density.
Muscular dystrophy: Genetic disorder of muscles.
Myasthenia gravis: Autoimmune disorder.

Understanding these disorders is important in the chapter Locomotion and Movement Class 11.

Flowchart / Mind Map (Text-Based)

Movement
→ Types of Movement
→ Amoeboid
→ Ciliary
→ Muscular

Muscular Movement
→ Skeletal System
→ Axial Skeleton
→ Appendicular Skeleton

→ Joints
→ Fibrous
→ Cartilaginous
→ Synovial

→ Muscles
→ Skeletal
→ Smooth
→ Cardiac

→ Sliding Filament Theory
→ Actin
→ Myosin
→ ATP
→ Calcium

Important Keywords with Meanings

Locomotion – Movement from one place to another
Movement – Change in position of body part
Sarcomere – Functional unit of muscle
Myofibril – Contractile thread in muscle fiber
Actin – Thin filament protein
Myosin – Thick filament protein
Synovial joint – Freely movable joint
Osteoporosis – Bone density loss
Arthritis – Joint inflammation
H-zone – Lighter region of A-band

Important Questions and Answers

10 Short Answer Questions

Define locomotion.
Locomotion is movement of the whole body from one place to another.
What is a sarcomere?
Sarcomere is the functional unit of muscle contraction.
Name three types of muscles.
Skeletal, smooth and cardiac muscles.
What is axial skeleton?
It forms the central axis of the body.
Give example of hinge joint.
Elbow joint.
What is osteoporosis?
Loss of bone density.
Define muscular movement.
Movement caused by contraction of muscles.
What is the role of ATP?
Provides energy for muscle contraction.
What are pseudopodia?
Temporary cytoplasmic projections.
What is arthritis?
Inflammation of joints.

10 Long Answer Questions

Explain sliding filament theory.
The sliding filament theory states that muscle contraction occurs due to sliding of actin over myosin filaments. Cross bridges form, ATP is hydrolyzed, sarcomere shortens, and contraction occurs.
Describe human skeletal system.
The skeletal system consists of 206 bones divided into axial and appendicular skeleton. It provides support, protection, and aids in locomotion and movement.

10 Long Answer Questions with Answers

Chapter: Locomotion and Movement Class 11 Biology

These long answer questions are designed as per NCERT pattern and are helpful for board exams and competitive exams like NEET.

1. Describe the human skeletal system in detail.

Answer:
The human skeletal system forms the framework of the body and consists of 206 bones in adults. It provides shape, support, and protection to internal organs. It also helps in locomotion and movement by providing attachment to muscles.

The skeletal system is divided into two main parts:

(a) Axial Skeleton – It forms the central axis of the body and includes:

Skull (22 bones)
Vertebral column (26 bones)
Ribs (12 pairs)
Sternum

The axial skeleton protects vital organs like the brain, spinal cord, heart, and lungs.

(b) Appendicular Skeleton – It consists of:

Pectoral girdle
Pelvic girdle
Forelimbs and hindlimbs

The appendicular skeleton mainly helps in movement and locomotion.

Thus, the skeletal system plays an important role in the chapter Locomotion and Movement Class 11.

2. Explain the sliding filament theory of muscle contraction.

Answer:
The sliding filament theory explains the mechanism of muscle contraction. It was proposed by Huxley and Hanson.

According to this theory:

Muscle contraction occurs due to the sliding of thin actin filaments over thick myosin filaments.
The length of actin and myosin remains constant.
The sarcomere shortens during contraction.

Steps involved:

Nerve impulse reaches the muscle fiber.
Calcium ions are released from sarcoplasmic reticulum.
Myosin heads attach to actin forming cross bridges.
ATP is hydrolyzed, and myosin pulls actin inward.
I-band and H-zone decrease in size.
The muscle contracts.

This theory is very important in Locomotion and Movement Class 11.

3. Describe the structure of a skeletal muscle fiber.

Answer:
A skeletal muscle is made up of long cylindrical cells called muscle fibers. Each muscle fiber is multinucleated and surrounded by a membrane called sarcolemma.

Inside the muscle fiber:

Sarcoplasm contains myofibrils.
Myofibrils consist of repeating units called sarcomeres.
Sarcomere is the functional unit of muscle contraction.

Important parts of sarcomere:

Z-line
I-band (light band)
A-band (dark band)
H-zone
M-line

Actin forms thin filaments, while myosin forms thick filaments.

4. Explain different types of joints with examples.

Answer:
Joints are points where two bones meet. They help in locomotion and movement.

Types of joints:

1. Fibrous joints:

Immovable
Example: Sutures of skull

2. Cartilaginous joints:

Slightly movable
Example: Between vertebrae

3. Synovial joints:

Freely movable
Contain synovial fluid

Types of synovial joints:

Ball and socket (Shoulder)
Hinge (Elbow)
Pivot (Atlas-axis)
Gliding (Wrist)
Saddle (Thumb)
Condyloid (Wrist joint)

Synovial joints are most important for body movement.

5. Differentiate between skeletal, smooth and cardiac muscles.

Answer:

Feature	Skeletal Muscle	Smooth Muscle	Cardiac Muscle
Control	Voluntary	Involuntary	Involuntary
Striations	Present	Absent	Present
Location	Attached to bones	Internal organs	Heart
Nuclei	Multinucleated	Single nucleus	Single nucleus
Function	Body movement	Organ movement	Pumping blood

This difference is frequently asked in exams from Locomotion and Movement Class 11.

6. Describe the mechanism of muscle contraction.

Answer:
Muscle contraction involves coordinated interaction between actin and myosin.

Steps:

Motor neuron sends impulse.
Acetylcholine is released at neuromuscular junction.
Calcium ions are released.
Cross bridges form.
Power stroke occurs.
ATP binds and breaks cross bridge.
Relaxation occurs when calcium returns.

ATP is essential for both contraction and relaxation.

7. Write a note on disorders of skeletal system.

Answer:
Common skeletal disorders include:

1. Arthritis:
Inflammation of joints causing pain and stiffness.

2. Osteoporosis:
Decrease in bone mass due to calcium deficiency or aging.

3. Gout:
Uric acid crystals accumulate in joints.

4. Scoliosis:
Abnormal curvature of spine.

These disorders affect locomotion and movement.

8. Explain amoeboid, ciliary and muscular movements.

Answer:

Amoeboid Movement:
Occurs due to pseudopodia. Seen in Amoeba and WBCs.

Ciliary Movement:
Occurs due to beating of cilia. Seen in respiratory tract and fallopian tubes.

Muscular Movement:
Occurs due to contraction and relaxation of muscles. Most common in vertebrates.

These three types explain basic movement concepts in Locomotion and Movement Class 11.

9. Describe the structure and functions of synovial joints.

Answer:
Synovial joints are freely movable joints.

Structure:

Articular cartilage
Synovial cavity
Synovial fluid
Ligaments
Joint capsule

Functions:

Provide flexibility
Reduce friction
Enable smooth movement
Absorb shock

They play a major role in body locomotion.

10. Discuss the role of calcium and ATP in muscle contraction.

Answer:
Calcium and ATP are essential for muscle contraction.

Role of Calcium:

Released from sarcoplasmic reticulum.
Binds to troponin.
Exposes binding sites on actin.

Role of ATP:

Provides energy for cross bridge formation.
Required for power stroke.
Helps in detachment of myosin head.
Essential for muscle relaxation.

30 Multiple Choice Questions (MCQs) – Locomotion and Movement Class 11

Chapter Focus: Locomotion and Movement

1. Movement of white blood cells is an example of:

a) Ciliary movement
b) Muscular movement
c) Amoeboid movement
d) Flagellar movement
Answer: c

2. Number of bones in an adult human is:

a) 200
b) 206
c) 208
d) 210
Answer: b

3. The functional unit of muscle contraction is:

a) Myofibril
b) Sarcomere
c) Actin
d) Myosin
Answer: b

4. Which joint is present between atlas and axis?

a) Hinge joint
b) Pivot joint
c) Ball and socket joint
d) Gliding joint
Answer: b

5. The protein that forms thick filament is:

a) Actin
b) Myosin
c) Troponin
d) Tropomyosin
Answer: b

6. The H-zone is present in:

a) I-band
b) A-band
c) Z-line
d) Sarcolemma
Answer: b

7. Synovial joints are:

a) Immovable
b) Slightly movable
c) Freely movable
d) Fixed joints
Answer: c

8. Example of ball and socket joint:

a) Knee
b) Elbow
c) Shoulder
d) Skull
Answer: c

9. Which muscle is involuntary and striated?

a) Skeletal
b) Smooth
c) Cardiac
d) Visceral
Answer: c

10. Calcium ions are stored in:

a) Mitochondria
b) Golgi body
c) Sarcoplasmic reticulum
d) Nucleus
Answer: c

11. The Z-line is found in:

a) A-band
b) I-band
c) H-zone
d) M-line
Answer: b

12. Osteoporosis is related to:

a) Muscle degeneration
b) Bone density loss
c) Joint inflammation
d) Nerve damage
Answer: b

13. Arthritis is:

a) Muscle pain
b) Nerve disorder
c) Joint inflammation
d) Bone fracture
Answer: c

14. The energy currency of muscle contraction is:

a) ADP
b) AMP
c) ATP
d) NADH
Answer: c

15. Which of the following is a flat bone?

a) Femur
b) Vertebra
c) Sternum
d) Carpals
Answer: c

16. Long bones are found in:

a) Skull
b) Limbs
c) Vertebral column
d) Ribs
Answer: b

17. Sliding filament theory was proposed by:

a) Watson and Crick
b) Huxley and Hanson
c) Mendel
d) Darwin
Answer: b

18. The thin filament mainly contains:

a) Myosin
b) Actin
c) Keratin
d) Collagen
Answer: b

19. The vertebral column belongs to:

a) Appendicular skeleton
b) Axial skeleton
c) Limb skeleton
d) Pelvic girdle
Answer: b

20. Which joint allows movement in one plane?

a) Ball and socket
b) Pivot
c) Hinge
d) Saddle
Answer: c

21. The structural unit of a myofibril is:

a) Myosin
b) Actin
c) Sarcomere
d) Z-line
Answer: c

22. Smooth muscles are:

a) Voluntary
b) Striated
c) Multinucleated
d) Involuntary and non-striated
Answer: d

23. The pelvic girdle is part of:

a) Axial skeleton
b) Appendicular skeleton
c) Skull
d) Vertebral column
Answer: b

24. Muscular dystrophy affects:

a) Bones
b) Joints
c) Muscles
d) Nerves
Answer: c

25. Gliding joint is found in:

a) Knee
b) Wrist
c) Shoulder
d) Hip
Answer: b

26. Which band disappears during contraction?

a) A-band
b) I-band
c) M-line
d) Sarcolemma
Answer: b

27. Sarcolemma is:

a) Muscle cytoplasm
b) Muscle cell membrane
c) Connective tissue
d) Nerve covering
Answer: b

28. Red muscle fibers contain more:

a) Fat
b) Glycogen
c) Myoglobin
d) Collagen
Answer: c

29. Amoeboid movement is caused by:

a) Cilia
b) Flagella
c) Pseudopodia
d) Muscles
Answer: c

30. The sternum is part of:

a) Appendicular skeleton
b) Axial skeleton
c) Pelvic girdle
d) Pectoral girdle
Answer: b

Exam Tips for Locomotion and Movement Class 11

Practice labeled diagrams of sarcomere.
Revise types of joints carefully.
Understand sliding filament theory stepwise.
Remember differences between three muscle types.
Solve MCQs for competitive exams.

Value-Based Questions

Why is regular exercise important?
It strengthens muscles and bones.
Why should calcium intake be adequate?
To prevent osteoporosis.
Why should posture be correct?
To avoid skeletal disorders.
Why is early diagnosis of arthritis important?
Prevents joint damage.
Why is coordination important in movement?
Ensures smooth locomotion.

Conclusion

The chapter Locomotion and Movement is one of the most important chapters in NCERT Biology. It explains how the human body performs movement through the coordinated action of bones, joints, and muscles. From understanding the skeletal framework to the sliding filament theory of muscle contraction, this chapter builds a strong conceptual base for higher studies in medical and life sciences.

Mastering Locomotion and Movement helps students perform well in board exams and competitive exams like NEET. The chapter strengthens understanding of muscle contraction, joint mechanisms, and skeletal disorders. Regular revision of notes, keywords, diagrams, MCQs, and important questions ensures better retention.

Students should focus on diagrams, flowcharts, and conceptual clarity to score high marks. With proper preparation and structured study, Locomotion and Movement becomes easy and scoring.

By revising the summary, practicing MCQs, and understanding important questions, students can confidently attempt any question from the chapter. This comprehensive guide on Locomotion and Movement Class 11 provides everything needed for quick revision, exam preparation, and concept clarity.

10 Assertion–Reason Questions

Chapter: Locomotion and Movement Class 11 Biology

Directions:
For each question, choose the correct option:
A. Both Assertion (A) and Reason (R) are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.

1.

Assertion (A): Sarcomere shortens during muscle contraction.
Reason (R): Actin and myosin filaments decrease in length during contraction.

Answer: C
Sarcomere shortens, but actin and myosin do not change length; they slide over each other.

2.

Assertion (A): Synovial joints allow free movement.
Reason (R): They contain synovial fluid in the joint cavity.

Answer: A
Synovial fluid reduces friction and enables free movement.

3.

Assertion (A): Cardiac muscles are involuntary and striated.
Reason (R): Cardiac muscles are present in the heart and work without conscious control.

Answer: A

4.

Assertion (A): Calcium ions are necessary for muscle contraction.
Reason (R): Calcium binds to troponin and exposes active sites on actin.

Answer: A

5.

Assertion (A): The axial skeleton helps in locomotion.
Reason (R): The axial skeleton forms the central axis and protects vital organs.

Answer: B
Both are true, but protection is not the direct reason for locomotion.

6.

Assertion (A): Smooth muscles are multinucleated.
Reason (R): Smooth muscles are involuntary muscles found in visceral organs.

Answer: D
Assertion is false; smooth muscles are uninucleate. Reason is true.

7.

Assertion (A): I-band decreases in length during muscle contraction.
Reason (R): Actin filaments slide over myosin filaments.

Answer: A

8.

Assertion (A): Osteoporosis leads to fragile bones.
Reason (R): It is caused by a decrease in bone mass and calcium deficiency.

Answer: A

9.

Assertion (A): H-zone disappears during muscle contraction.
Reason (R): Thick filaments shorten during contraction.

Answer: C
H-zone disappears, but thick filaments do not shorten.

10.

Assertion (A): Muscular movement is the most common type of movement in higher animals.
Reason (R): It occurs due to contraction and relaxation of muscles attached to bones.

Answer: A

Sample Question Paper

Locomotion and Movement Class 11 Biology – Sample Paper with Solutions

Subject: Biology
Class: XI
Chapter: Locomotion and Movement
Time: 3 Hours
Maximum Marks: 70

This sample paper for Locomotion and Movement Class 11 is designed as per NCERT pattern and is useful for school exams and competitive preparation.

Section A – MCQs (1 × 10 = 10 Marks)

Choose the correct option:

The functional unit of muscle contraction is:
a) Myofibril
b) Sarcomere
c) Actin
d) Myosin
Number of bones in adult human:
a) 200
b) 206
c) 210
d) 208
The pivot joint is found between:
a) Femur and tibia
b) Atlas and axis
c) Humerus and scapula
d) Radius and ulna
Thick filaments are made of:
a) Actin
b) Myosin
c) Collagen
d) Keratin
Osteoporosis mainly affects:
a) Muscles
b) Joints
c) Bones
d) Nerves
I-band contains:
a) Only thick filaments
b) Only thin filaments
c) Both thick and thin
d) No filaments
Smooth muscles are:
a) Voluntary
b) Striated
c) Involuntary and non-striated
d) Multinucleated
Synovial fluid functions to:
a) Increase friction
b) Reduce friction
c) Produce hormones
d) Carry oxygen
The sternum is part of:
a) Appendicular skeleton
b) Axial skeleton
c) Pelvic girdle
d) Pectoral girdle
Calcium ions are released from:
a) Mitochondria
b) Golgi body
c) Sarcoplasmic reticulum
d) Ribosome

Section B – Very Short Answer (2 × 5 = 10 Marks)

Define locomotion.
What is a sarcomere?
Name two types of movements other than muscular movement.
What is arthritis?
Name the three types of muscles.

Section C – Short Answer (3 × 6 = 18 Marks)

Differentiate between axial and appendicular skeleton.
Explain hinge and ball-and-socket joints with examples.
Describe the structure of a skeletal muscle fiber.
What changes occur in sarcomere during contraction?
Write a short note on osteoporosis and its causes.
Explain amoeboid movement.

Section D – Long Answer (5 × 4 = 20 Marks)

Describe the sliding filament theory of muscle contraction.
Explain the types of synovial joints with neat labeled diagrams.
Describe the human skeletal system in detail.
Discuss the mechanism of muscle contraction.

Section E – Case Study Based Questions (1 × 12 = 12 Marks)

A 60-year-old woman suffers from weak and fragile bones and frequent fractures.

(a) Name the disorder.
(b) What causes this condition?
(c) How can it be prevented?
(d) Which mineral is essential for bone health?

Solutions – Sample Paper

Locomotion and Movement Class 11 Biology – Detailed Solutions

Section A – MCQ Solutions (1 × 10 = 10 Marks)

Answer: (b) Sarcomere
Sarcomere is the structural and functional unit of muscle contraction.
Answer: (b) 206
An adult human skeleton consists of 206 bones.
Answer: (b) Atlas and axis
Pivot joint between atlas and axis allows rotational movement of head.
Answer: (b) Myosin
Thick filaments of muscle are made of myosin protein.
Answer: (c) Bones
Osteoporosis is a disorder affecting bone density.
Answer: (b) Only thin filaments
I-band contains only actin (thin filaments).
Answer: (c) Involuntary and non-striated
Smooth muscles are involuntary and lack striations.
Answer: (b) Reduce friction
Synovial fluid lubricates joints to reduce friction.
Answer: (b) Axial skeleton
Sternum forms part of the rib cage in axial skeleton.
Answer: (c) Sarcoplasmic reticulum
Calcium ions required for contraction are released from sarcoplasmic reticulum.

Section B – Very Short Answer Solutions (2 × 5 = 10 Marks)

Locomotion is the movement of the whole body from one place to another.
Sarcomere is the functional unit of muscle contraction located between two Z-lines.
Two types of movement other than muscular movement are:

Amoeboid movement
Ciliary movement

Arthritis is inflammation of joints causing pain, swelling and stiffness.
Three types of muscles:

Skeletal muscles
Smooth muscles
Cardiac muscles

Section C – Short Answer Solutions (3 × 6 = 18 Marks)

16. Difference Between Axial and Appendicular Skeleton

Feature	Axial Skeleton	Appendicular Skeleton
Position	Central axis	Limbs and girdles
Includes	Skull, vertebral column, ribs, sternum	Pectoral girdle, pelvic girdle, limbs
Function	Protection and support	Movement and locomotion

17. Hinge and Ball-and-Socket Joints

Hinge Joint:
Allows movement in one plane only. Example: Elbow, knee.
Ball-and-Socket Joint:
Allows movement in all directions. Example: Shoulder, hip.

18. Structure of Skeletal Muscle Fiber

Long, cylindrical and multinucleated cells.
Covered by sarcolemma.
Contains myofibrils.
Myofibrils consist of repeating units called sarcomeres.
Sarcomeres contain actin (thin) and myosin (thick) filaments.

19. Changes in Sarcomere During Contraction

I-band shortens.
H-zone disappears.
A-band remains constant.
Z-lines move closer.
Overall sarcomere shortens.

20. Osteoporosis

Osteoporosis is a skeletal disorder characterized by reduced bone mass and density.
Causes:

Aging
Calcium deficiency
Hormonal imbalance
Lack of exercise

21. Amoeboid Movement

Amoeboid movement occurs due to formation of pseudopodia.
Seen in:

Amoeba
White blood cells

Cytoplasm flows in the direction of movement.

Section D – Long Answer Solutions (5 × 4 = 20 Marks)

22. Sliding Filament Theory

The sliding filament theory explains muscle contraction.

Proposed by Huxley and Hanson.
Actin filaments slide over myosin filaments.
Cross bridges form between actin and myosin.
ATP provides energy.
I-band and H-zone decrease.
Sarcomere shortens.

Length of filaments remains constant.

23. Types of Synovial Joints

Synovial joints are freely movable joints.

Types:

Hinge joint (Elbow)
Ball-and-socket joint (Shoulder)
Pivot joint (Atlas-axis)
Gliding joint (Wrist)
Saddle joint (Thumb)
Condyloid joint (Wrist)

They contain synovial fluid that reduces friction.

24. Human Skeletal System

The human skeleton has 206 bones.

Axial Skeleton:

Skull
Vertebral column
Ribs
Sternum

Appendicular Skeleton:

Pectoral girdle
Pelvic girdle
Upper limbs
Lower limbs

Functions:

Support
Protection
Movement
Blood cell formation

25. Mechanism of Muscle Contraction

Steps involved:

Nerve impulse reaches muscle fiber.
Acetylcholine is released.
Calcium ions are released.
Cross bridges form.
Power stroke occurs.
ATP binds and detaches myosin head.
Muscle relaxes.

ATP and calcium are essential for contraction.

Section E – Case Study Solution (12 Marks)

(a) The disorder is Osteoporosis.

(b) It is caused by:

Decrease in bone mass
Calcium deficiency
Hormonal imbalance
Aging

Balanced diet rich in calcium and vitamin D
Regular exercise
Sunlight exposure

(d) Essential mineral: Calcium

Additional Sample Paper

Locomotion and Movement Class 11 Biology – Practice Test Paper 2

Subject: Biology
Class: XI
Chapter: Locomotion and Movement
Time: 3 Hours
Maximum Marks: 70

This additional sample paper for Locomotion and Movement Class 11 is designed according to the latest NCERT pattern. It includes MCQs, short answers, long answers, and case-based questions for full syllabus revision.

Section A – MCQs (1 × 12 = 12 Marks)

Choose the correct answer:

The light band of sarcomere is:
a) A-band
b) I-band
c) H-zone
d) M-line
The longest bone in the human body is:
a) Humerus
b) Tibia
c) Femur
d) Radius
Which joint allows rotational movement?
a) Hinge
b) Pivot
c) Saddle
d) Gliding
The Z-line is present in:
a) A-band
b) H-zone
c) I-band
d) M-line
Cardiac muscles are found in:
a) Lungs
b) Intestine
c) Heart
d) Brain
The dark band of sarcomere is:
a) I-band
b) A-band
c) Z-line
d) Sarcolemma
Red muscle fibers contain high amount of:
a) Glycogen
b) Fat
c) Myoglobin
d) Calcium
Which disorder is caused by accumulation of uric acid crystals?
a) Osteoporosis
b) Arthritis
c) Gout
d) Myasthenia gravis
The pelvic girdle is part of:
a) Axial skeleton
b) Appendicular skeleton
c) Skull
d) Rib cage
Sarcolemma refers to:
a) Muscle cytoplasm
b) Muscle membrane
c) Joint capsule
d) Bone covering
During contraction, which band remains constant?
a) I-band
b) H-zone
c) A-band
d) Z-line
Ciliary movement occurs in:
a) Skeletal muscle
b) Amoeba
c) Respiratory tract
d) Bones

Section B – Very Short Answer (2 × 6 = 12 Marks)

Define movement.
What is synovial fluid?
Name two flat bones.
What is muscular dystrophy?
Define sarcoplasmic reticulum.
What is meant by muscle tone?

Section C – Short Answer (3 × 6 = 18 Marks)

Differentiate between red and white muscle fibers.
Explain the structure of a synovial joint.
Write a short note on amoeboid movement.
Describe the functions of skeletal system.
What changes occur in muscle during relaxation?
Explain the role of ATP in muscle contraction.

Section D – Long Answer (5 × 4 = 20 Marks)

Describe the sliding filament theory with diagrammatic explanation.
Explain types of muscles with suitable examples.
Describe the human vertebral column.
Discuss common skeletal disorders and their prevention.

Section E – Case Study (8 Marks)

A young athlete complains of severe joint pain and swelling after an injury during practice.

(a) Which type of joint is most commonly injured in sports?
(b) What is the role of ligaments in joints?
(c) Why is synovial fluid important in joints?
(d) Suggest preventive measures for joint injuries.

SOLUTION

Detailed Solutions

Additional Sample Paper – Locomotion and Movement

Section A – MCQ Solutions (1 × 12 = 12 Marks)

(b) I-band
I-band is the light band of sarcomere and contains only thin filaments (actin).
(c) Femur
Femur is the longest and strongest bone in the human body.
(b) Pivot
Pivot joint allows rotational movement (example: atlas and axis).
(c) I-band
Z-line passes through the I-band and marks the boundary of sarcomere.
(c) Heart
Cardiac muscles are found only in the heart.
(b) A-band
A-band is the dark band of sarcomere and contains thick filaments.
(c) Myoglobin
Red muscle fibers contain high myoglobin and more mitochondria.
(c) Gout
Gout occurs due to accumulation of uric acid crystals in joints.
(b) Appendicular skeleton
Pelvic girdle is part of appendicular skeleton.
(b) Muscle membrane
Sarcolemma is the plasma membrane of muscle fiber.
(c) A-band
A-band remains constant during muscle contraction.
(c) Respiratory tract
Ciliary movement helps in clearing mucus from respiratory tract.

Section B – Very Short Answer Solutions (2 × 6 = 12 Marks)

Movement is a change in position of the whole body or its parts.
Synovial fluid is a lubricating fluid present in synovial joints that reduces friction.
Two flat bones:

Skull bones
Sternum

Muscular dystrophy is a genetic disorder characterized by progressive degeneration of skeletal muscles.
Sarcoplasmic reticulum is a specialized endoplasmic reticulum in muscle fibers that stores calcium ions.
Muscle tone is the continuous partial contraction of muscles which maintains posture.

Section C – Short Answer Solutions (3 × 6 = 18 Marks)

19. Difference Between Red and White Muscle Fibers

Feature	Red Fibers	White Fibers
Myoglobin	High	Low
Mitochondria	More	Fewer
Contraction	Slow and sustained	Fast and powerful
Fatigue	Resist fatigue	Fatigue quickly

20. Structure of Synovial Joint

A synovial joint consists of:

Joint capsule
Synovial membrane
Synovial cavity
Synovial fluid
Articular cartilage
Ligaments

Function: Allows smooth and free movement.

21. Amoeboid Movement

Amoeboid movement occurs through formation of pseudopodia.
It is seen in Amoeba and white blood cells.
Cytoplasm flows in the direction of pseudopodium formation.