The NCERT Solutions for Class 11 Biology Chapter 17 Locomotion and Movement explores the structure of muscles and the skeletal system. This chapter also explains the different functions of muscles and the way bones and joints work together to move. Students can refer to the detailed explanations to improve their conceptual understanding. The NCERT solutions are very helpful in building a strong foundation for school exams and competitive exams such as NEET.
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Locomotion and Movement Class 11 question answer discusses the human skeletal system, including bones, joints, and muscles, and highlights the role of ligaments and tendons. Focus has been laid on how skeletal muscles contract and interact with the skeleton. The Locomotion and Movement Class 11 Questions and Answers PDF includes common disorders like arthritis and osteoporosis. Practising with the NCERT Solutions for Class 11 allows students to answer questions more confidently.
Students can download the PDF from the link given below to make studying more organized and systematic. The Locomotion and Movement Class 11 Questions and Answers PDF helps in quick revisions and can be accessed anytime without the internet.
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Given below are the clear answers to all the exercise questions from this chapter. Students can refer to the Class 11 Biology Chapter 17 Locomotion and Movement question answer for quick revision. These solutions are prepared by subject experts and follow the latest NCERT curriculum.
Q2. Define the sliding filament theory of muscle contraction.
Answer:
Sliding filament theory of muscle contraction
1. The sliding filament theory was mainly proposed to explain the process of muscle contraction. This theory proposes that during muscle contraction, the thin filaments slide over the thick filaments, leading to shortening of the myofibrils.
2. Each muscle fiber possesses alternate light and dark bands, which contain a specialized contractile protein known as actin and myosin, respectively.
3. Actin refers to a thin contractile protein present in the light band, and is known as the I-band. On the other hand, myosin is a thick contractile protein present in the dark band and is known as the A-band.
4. An elastic fiber called the Z line bisects each I-band. To this z-line, the thin filament is firmly anchored. The central part of the thick filament that is not overlapped by the thin filament is known as the H-zone.
5. During muscle contraction, the myosin heads or cross-bridges come in close contact with the thin filaments, causing the thin filaments to be pulled towards the middle of the sarcomere. The Z line attached to the actin filaments is also pulled, leading to the shortening of the sarcomere. Hence, the length of the band remains constant as its original length, and the I-band shortens and the H-zone disappears.
Q3. Describe the important steps in muscle contraction.
Answer:
The process of muscle contraction includes the following events.
1. Depolarisation of Sarcolemma- In this event, a signal is sent by the central nervous system through a motor neuron, and it reaches the neuromuscular junction or motor end plate. The neuromuscular junction refers to the junction between a motor neuron and the sarcolemma of the muscle fibre. The reception of the signal by the neuromuscular junction causes the acetylcholine, which is a neurotransmitter, to be released and sets the action potential in the sarcolemma.
2. Release of Calcium Ions- This step includes the transmission of the action potential by the sarcolemma to the sarcoplasmic reticulum to release calcium ions in the sarcoplasm.
3. Conformational Changes in Actin Filaments- The calcium ions thus released bind to the troponin and tropomyosin on active filaments, changing the three-dimensional shape of the actin-troponin-tropomyosin complex. This causes the active site for myosin, which is found on the actin filament, to be exposed.
4. Activation of Myosin Heads- Later on, the myosin heads also get activated, and they release energy by the hydrolysis of ATP, resulting in the binding of myosin heads to the active sites present on the actin filaments. This leads to the formation of the actin-myosin cross-bridge.
5. Sliding of Actin Filaments over Myosin- After the formation of cross-bridges, the myosin head rotates to pull the actin filament towards the centre of the A-band, i.e, the H-zone. The Z-line attached to the actin filaments is also pulled inwards, resulting in the contraction of the sarcomere. During contraction, the I-band shortens, while the A-band retains its length. This causes the muscles to contract.Q4. Write true or false. If false, change the statement so that it is true.
(a) Actin is present in the thin filament
(b) The H-zone of striated muscle fibre represents both thick and thin filaments.
(c) The human skeleton has 206 bones.
(d) There are 11 pairs of ribs in a man.
(e) Sternum is present on the ventral side of the body.
Answer:
(a) Actin is present in the thin filament
True statement
(b) The H-zone of striated muscle fibre represents both thick and thin filaments.
False statement. H -zone of striated muscle fibre is the central part of the thick filament that is not overlapped by the thin filament.
(c) The human skeleton has 206 bones
True statement.
(d) There are 11 pairs of ribs in a man.
False statement. There are 12 pairs of ribs in a man.
(e) Sternum is present on the ventral side of the body.
True statement
Q5. Write the difference between :
(a) Actin and Myosin
Answer:
The differences between actin and myosin are as follows:
Actin | Myosin |
Actin refers to the thin contractile protein | Myosin refers to the thick contractile protein |
Actin is found in light bands called isotropic bands | Myosin is found in dark bands called anisotropic bands |
Q5. Write the difference between :
(b) Red and White muscles
Answer:
Red muscle fibre | White muscle fibre |
These are thin and smaller in size | These are thick and larger |
Due to the presence of myoglobin, they are red | Due to the presence of only a small amount of myoglobin, they are white |
These carry out slow and sustained contractions | These carry out fast contractions for shorter durations. |
Q5. Write the difference between :
(c) Pectoral and Pelvic girdle
Answer:
Pectoral girdle | Pelvic girdle |
Skeletal support where the forelimbs are attached | A skeletal support where the hindlimbs are attached |
It includes two bones, i.e. the clavicle and the scapula | It includes three bones, i.e., the ileum, pubis, and ischium |
Q6. Match Column I with Column II :
Column I Column II
(a) Smooth muscle (i) Myoglobin
(b) Tropomyosin (ii) Thin filament
(c) Red muscle (iii) Sutures
(d) Skull (iv) Involuntary
Answer:
The correct matching is as follows: a-iv, b-ii, c-i, d-iii
| Column I | Column II |
| (a) Smooth muscle | (iv) Involuntary |
| (b) Tropomyosin | (ii) Thin filament |
| (c) Red muscle | (i) Myoglobin |
| (d) Skull | (iii) Sutures |
Q7. What are the different types of movements exhibited by the cells of the human body?
Answer:
The different types of movements exhibited by the cells of the human body are as follows:
1. Amoeboid movement - The leucocytes present in the blood show amoeboid movement. During tissue damage, these blood cells move in an amoeboid manner (by forming temporary pseudopodia) from the circulatory system towards the site of injury to initiate an immune response.
2. Ciliary movement- The reproductive cells, such as sperm and ova, show ciliary movement. The passage of ova through the fallopian tube towards the uterus is facilitated by this movement.
3. Muscular movement- The muscle cells of the human body show muscular movement. These contract and relax to bring about the movement. E.g., Movements of limbs, tongue, and jaws are examples of muscular movements.
Q8. How do you distinguish between a skeletal muscle and a cardiac muscle?
Answer:
The differences between skeletal muscles and cardiac muscles are as follows:
Skeletal muscle | Cardiac muscle |
The function of skeletal muscles is voluntary. | Cardiac muscles function involuntarily. |
The cells of these muscles are unbranched | The cells of these muscles are branched |
Intercalated discs between the cells are absent | Intercalated discs between the cells are present |
These consist of alternate light and dark bands | These possess bands that are faint |
These are voluntary | These are involuntary |
They help in locomotory actions and body posture | Cardiac muscles help in the movements of the heart |
Q9. Name the type of joint between the following:-
(a) atlas/axis
Answer:
The atlas and axis form a pivot joint.
Q9. Name the type of joint between the following:-
(b) carpal/metacarpal of thumb
Answer:
The carpal and metacarpal bones of the thumb form a saddle joint.
Q9. Name the type of joint between the following:-
(c) between phalanges
Answer:
between the phalanges' hinge joint
Q9. Name the type of joint between the following:-
(d) femur/acetabulum
Answer:
The femur/acetabulum form ball and socket joints.
Q9. Name the type of joint between the following:-
(e) between cranial bones
Answer:
Between cranial bones, fibrous joints are present.
Q9. Name the type of joint between the following:-
(f) between the pubic bones in the pelvic girdle
Answer:
Between the pubic bones in the pelvic girdle, cartilaginous joints are present.
Q10. Fill in the blank spaces:
(a) All mammals (except a few) have __________ cervical vertebra.
(b) The number of phalanges in each limb of a human is __________
(c) Thin filament of myofibril contains 2 ‘F’ actins and two other proteins, namely __________ and __________.
(d) In a muscle fibre, Ca++ is stored in __________
(e)The __________ and __________ pairs of ribs are called floating ribs.
(f) The human cranium is made of __________ bones.
Answer:
(a) All mammals (except a few) have seven cervical vertebrae.
(b) The number of phalanges in each limb of a human is 14.
(c) Thin filament of myofibril contains 2 ‘F’ actins and two other proteins, namely troponin and tropomyosin.
(d) In a muscle fibre, Ca++ is stored in the sarcoplasmic reticulum.
(e) The 11th and 12th pairs of ribs are called floating ribs.
(f) The human cranium is made of eight bones.
Also, check the NCERT Books and the NCERT Syllabus here:
To answer Locomotion and Movement questions correctly and effectively, follow the given steps:
Get familiar with topics like modes of movement, muscle organisation, and skeletal systems.
Learn the mechanism of muscle contraction, i.e., actin and myosin interaction. Students can refer to the Class 11 Biology Chapter 17 Locomotion and Movement question answer.
Go through the organisation and types of joints with examples again.
Focus on muscular and skeletal system disorders like arthritis and osteoporosis.
Practice muscle, bone, and joint diagrams provided in the Class 11 Biology Locomotion and Movement question answer.
NCERT Solutions for Class 11: Subject-wise
Locomotion and movement are important life processes that enable organisms to move from one place to another and respond to their environment. In humans, these movements are made possible by the coordinated action of the skeletal system, muscular system, and joints.
Take a look at some of the important questions given below that help in understanding the concept. For more questions, students can also refer to the answers given in the NCERT Solutions for Class 11 Biology Chapter 17 Locomotion and Movement. These provide conceptual clarity and improve performance as well.
Question 1: Among the provided options, which combination of bones actively contributes to the locomotion of a cricket player rapidly chasing a ball on the field?
Options:
1- Femur, malleus, tibia, metatarsals
2- Pelvis, ulna, patella, tarsals
3- Sternum, femur, tibia, fibula
4- Tarsals, femur, metatarsals, tibia
Answer:
The tarsals are a group of bones located in the foot and ankle region, which provide stability and support during movement. The femur, the largest bone in the human body, plays a crucial role in leg movement and provides strength and stability. The metatarsals are the long bones in the midfoot that connect to the toes. The tibia, commonly known as the shinbone, is essential for weight-bearing and provides support and stability.
Hence, the correct answer is option (4), Tarsals, femur, metatarsals, tibia
Question 2: Muscles with characteristic striations and involuntary are
Options:
1- Muscles in the wall of the alimentary canal
2- Muscles of the heart
3- Muscles assisting locomotion
4- Muscles of the eyelids
Answer:
Cardiac muscles are the primary tissue of the heart wall and are involuntary, striated muscles. With blood supplied by the coronary circulation, the cardiac muscle (myocardium) forms a thick middle layer between the inner layer (the endocardium) and the outer layer (the pericardium) of the heart wall.
Hence, the correct answer is option (2), Muscles of the heart
Question 3: Which one of the following is not a disorder of bone?
Options:
1- Arthritis
2- Osteoporosis
3- Rickets
4- Atherosclerosis
Answer:
The accumulation of fatty deposits, cholesterol, and other materials on the inner walls of arteries is known as atherosclerosis, and it has an impact on the cardiovascular system. Arterial stiffness is the result of these buildups forming plaques, which can impede blood flow and cause the arteries to stiffen and narrow.
Hence, the correct answer is option (4), Atherosclerosis
Question 4: The Intervertebral disc is found in the vertebral column of
Options:
1- Birds
2- Reptiles
3- Mammals
4- Amphibians
Answer:
Intervertebral discs are present between the vertebrae in mammals, acting as cushions that absorb shock and allow flexibility in the vertebral column. Other vertebrates like birds, reptiles, and amphibians either have fused vertebrae or lack these specialized discs.
Hence, the correct answer is option (3), Mammals
Question 5: Macrophages and leucocytes exhibit
Options:
1- Ciliary movement
2- Flagellar movement
3- Amoeboid movement
4- Gliding movement
Answer:
Macrophages and leucocytes move using amoeboid movement, which involves the extension of pseudopodia to crawl through tissues and engulf pathogens. This type of movement is essential for their role in immune defence.
Hence, the correct answer is option (3), Amoeboid movement
Question 6: Which ion plays a primary role in muscle contraction by binding to troponin?
Options:
1– Sodium (Na⁺)
2– Potassium (K⁺)
3– Calcium (Ca²⁺)
4– Chloride (Cl⁻)
Answer:
Calcium ions (Ca²⁺) are essential for muscle contraction. When an action potential reaches the muscle fibre, Ca²⁺ is released from the sarcoplasmic reticulum. These calcium ions bind to troponin, causing a conformational change that moves tropomyosin away from the binding sites on actin, allowing myosin to attach and initiate contraction.
Hence, the correct answer is option (3) Calcium (Ca²⁺).
Question 7: During a muscle contraction, the region that shortens is the
Options:
1– A-band
2– I-band
3– H-zone
4– Both I-band and H-zone
Answer:
During contraction, actin filaments slide over myosin, causing the I-band (actin-only region) and the H-zone (myosin-only region) to shorten. However, the A-band, which spans the entire length of the myosin filament, remains unchanged.
Hence, the correct answer is option (4), Both I-band and H-zone.
Question 8: Which of the following joints allows movement in all directions?
Options:
1- Hinge joint
2- Pivot joint
3- Ball and socket joint
4- Gliding joint
Answer:
A ball and socket joint allows movement in all directions. In this type of joint, the rounded end of one bone fits into the cup-shaped cavity of another bone, permitting movements such as flexion, extension, abduction, adduction, rotation, and circumduction. Examples include the shoulder joint and hip joint.
Hence, the correct answer is option (3), Ball and socket joint.
Question 9: The functional unit of skeletal muscle is known as the
Options:
1- Myofibril
2- Sarcomere
3- Myosin filament
4- Actin filament
Answer:
The sarcomere is the basic structural and functional unit of a myofibril. It is the segment between two successive Z-lines and contains a precise arrangement of actin and myosin filaments. Muscle contraction occurs due to the sliding of actin filaments over myosin filaments within the sarcomere.
Hence, the correct answer is option (2), Sarcomere.
Movement is one of the important features of living organisms, and in higher animals, it is coordinated with the help of bones, muscles, and joints. This chapter explains how different types of movements occur in the human body.
Students learn about different types of movements, such as amoeboid, ciliary, and muscular movement.
The chapter explains the structure of muscles and the mechanism of muscle contraction.
Through the Locomotion and Movement Class 11 question answer, learners understand the skeletal system and how bones and joints help in movement.
Disorders related to the musculoskeletal system, like arthritis and osteoporosis, are discussed in detail.
The Class 11 Biology Locomotion and Movement question answer also highlights how locomotion in humans is done through the coordination of muscles and bones.
The Locomotion and Movement chapter allows students to understand how different organisms move and the function of muscles and skeletal systems in locomotion. Important topics such as types of muscles, structure of skeletal muscles, and the sliding filament theory are also included.
The table below shows some extra topics and concepts that students need to prepare for NEET beyond the NCERT. These topics help in answering application-based questions in the exam. For a better understanding, students can study from the NCERT Solutions for Class 11 Biology Chapter 17 Locomotion and Movement.
Find chapter-wise solutions below, designed to help you understand concepts clearly and prepare effectively.
Frequently Asked Questions (FAQs)
The leucocytes present in the blood show amoeboid movement. During tissue damage, these blood cells move in an amoeboid manner (by forming temporary pseudopodia) from the circulatory system towards the site of injury to initiate an Immune response.
In Class 11 Biology, a muscle fiber, also known as a muscle cell, is a long, cylindrical cell containing numerous myofibrils that are made of repeating units called sarcomeres containing actin (thin filaments) and myosin (thick filaments).
The sarcomere, the fundamental unit of muscle contraction, shortens by the sliding of thin (actin) and thick (myosin) filaments past each other. They are driven by the myosin heads binding to actin and undergo a power stroke, a process requiring ATP and calcium ions.
Voluntary muscles, like those in your limbs, are under your own control, allowing you to move them intentionally, while involuntary muscles, such as those in your heart and digestive system, operate automatically without any voluntary effect.
The human body features three main types of joints: fibrous (immovable), cartilaginous (partially movable), and synovial (freely movable), with synovial joints further categorized into six types based on their structure and movement.
Calcium ion acts as a cofactor of the myosin ATPase enzyme, which hydrolyses ATP into ADP and inorganic phosphate so releasing energy. Energy stimulates the formation of actomyosin complexes, rotation of heads of myosin, and the inward sliding of actin filaments so causing muscle contraction.
As per sliding filament theory, when actin and myosin filaments slide towards each other, muscle contraction takes place. A neural signal reaching the neuromuscular junction releases a neurotransmitter (Acetylcholine) which generates an action potential in the sarcolemma.
A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is
| Option 1)
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Option 2)
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Option 4)
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An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range
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Option 2)
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Option 4)
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A particle is projected at 600 to the horizontal with a kinetic energy . The kinetic energy at the highest point
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Option 2)
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Option 4)
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In the reaction,
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Option 2)
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Option 4)
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How many moles of magnesium phosphate, will contain 0.25 mole of oxygen atoms?
| Option 1)
0.02 |
Option 2)
3.125 × 10-2 |
| Option 3)
1.25 × 10-2 |
Option 4)
2.5 × 10-2 |
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