1st PUC Biology Question Bank Chapter 20 Locomotion and Movement

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Karnataka 1st PUC Biology Question Bank Chapter 20 Locomotion and Movement

1st PUC Biology Locomotion and Movement NCERT Text Book Questions and Answers

Question 1.
Draw the diagram of a sarcomere of skeletal muscle showing different regions.
Answer:

Question 2.
Define the sliding filament theory of muscle contraction.
Answer:
Sliding filament theory states that contraction of a muscle fibre takes place by the sliding of the thin filaments over thick filaments.

Question 3.
Describe the important steps in muscle contraction.
Answer:
Steps in muscle contraction:
A nerve impulse arriving at the neuromuscular junctions initiates the contractile response.

• A neurotransmitter released at the neuromuscular junction enters the sarcomere through its membrane channel.
• The opening of the channel also results in the inflow of Na+ ions inside the sarcomere and generates an action potential that travels along the entire length of the muscle fibres.
• The sarcomere reticulum releases Ca++ ions, which bind with the specific sites present on the troponin component of the thin filament.
• Asa result of conformational changes in the troponin, the active sites on the F-actin are exposed.
• These are the active sites specific to the myosin head, which exhibits myosin-dependent ATPase activity.
• The myosin heads act as hooks and attach to F-actin to form cross-bridges.
• When the muscle is stimulated to contract, the cross-bridges move, pulling the two filaments past each other.
• When thousands of actin and myosin filaments interact this way the entire muscle cell shortens.

This concept is the sliding filament theory.

Question 4.
Write true or false. If false change the statement so that it is true.

1. Actin is present in the thin filament
2. H-zone of striated muscle fiber represents both thick and thin filaments.
3. The human skeleton has 206 bones.
4. There are 11 pairs of ribs in man.
5. The sternum is present on the ventral side of the body.

Answer:

1. True
2. False; H – zone represents thick filaments.
3. True
4. False; There are 12 pairs of ribs.
5. True.

Question 5.
Write the difference between:
(a) Actin and Myosin
(b) Red and White muscles
(c) Pectoral and Pelvic girdle
Answer:
(a) Actin filaments are thinner as compared to the myosin filaments. Actin filament exists in two forms namely globular actin or G actin and fibrous actin of F- actin. It also contains two proteins namely tropomyosin and troponin. Myosin filament or myofibril consists of two portions, head, and tail. The head is formed of heavy meromyosin (HMM) and the tail is formed of light meromyosin (LMM). The myosin head possesses contractile property as well as ATPase activity.

(b) Red and White muscles
Answer:

Red Muscle	White Muscle
(a) Red in colour due to the presence of large amount of myoglobin (b) Thin (c) Slow and sustained contraction (d) Depend on aerobic metabolism for energy (e) Presence of large amount  of mitochondria (f) Perform sustained work for a long time. (g) Blood capillaries more, eg: Extensor muscle on the back of the human body.	(a) Lesser amount of myoglobin, hence white in colour (b) Thick (c) Contraction rate is fast (d) Depend  on anaerobic metabolism for energy (e) Presence of small amount of mitochondria (f) Perform strenuous work for a short time. (g) Blood capillaries less, eg: Muscles of the eyeball.

(c) Pectoral and Pelvic girdle
Answer:

Pectoral girdle	Pelvic girdle
(i) Connects forelimb with axial skeleton	(i) Connects leg with the axial skeleton
(ii) Each half is formed of two bones, clavide and scapula	(ii) Each half is formed  of three bones ilium, ischium and pubis
(iii) Two halves are not fused	(iii) Two halves are fused
(iv) Found in backside of thorax	(iv) Found in hip region
(v) Cavity is known as glenoid cavity.	(v) A cavity is known as acetabulum

Question 6.
Match Column I with Column II:

Column I – Column – II

(a) Smooth muscle – (I) Myoglobln
(b) Tropomyosin – (II) Thin filament
(c) Red muscle – (III) Sutures
(d) Skull – (lV) Involuntary
Answer:
(a) (iv)
(b) (ii)
(c) (i)
(d) (iii)

Question 7.
What are the different types of movements exhibited by the cells of the human body?
Answer:
Cells of the human body exhibit three main types of movements, namely, amoeboid, ciliary and muscular. Some specialized cells in our body like macrophages and leucocytes in blood exhibit amoeboid movement. It is affected by pseudopodia formed by the streaming of protoplasm (as in Amoeba). Cytoskeletal elements like microfilaments are also involved in the amoeboid movement.

Ciliary movement occurs in most of our internal tubular organs which are lined by ciliated epithelium. The coordinated movements of cilia in the trachea help us in removing dust particles and some of the foreign substances inhaled along with the atmospheric air. Passage of ova through the female reproductive tract is also facilitated by the ciliary movement. Movement of our limbs, jaws, tongue, etc, requires muscular movement. The contractile property of muscles is effectively used for locomotion and other movements by human beings and the majority of multicellular organisms. Locomotion requires a perfect coordinated activity of muscular, skeletal, and neural systems.

Question 8.
How do you distinguish between a skeletal muscle and a cardiac muscle?
Answer:
Skeletal muscle: Skeletal muscles are closely associated with skeletal components of the body. They have a striped appearance under the microscope and hence are called striated muscles. As their activities are under the voluntary control of the nervous system, they are known as voluntary muscles too. They are primarily involved in locomotory actions and changes in body postures.

Cardiac muscles: Cardiac muscles are the muscles of the heart. Many cardiac muscle cells assemble in a branching pattern to form a cardiac muscle. Based on appearance, cardiac muscles are striated. They are involuntary in nature as the nervous system does not control their activities directly.

Question 9.
Name the type of Joint between the following:

1. Atlas/axis
2. Carpal/metacarpal of the thumb
3. Between phalanges
4. Femur/acetabulum
5. Between cranial bones
6. Between pubic bones in the pelvic girdle

Answer:

1. Pivot joint
2. Saddle joint
3. Gliding joint
4. Ball and socket joint
5. Fibrous joint
6. Cartilaginous joint

Question 10.
Fill in the blank spaces:

1. All mammals (except a few) have ……………… cervical vertebra.
2. The number of phalanges in each limb of humans………………
3. A thin filament of myofibril contains 2 ‘F’ actins and two other proteins namely ……………… and ………………
4. In a muscle fibre Ca++ is stored in ………………
5. ……………… and pairs of ribs are called floating ribs……………….
6. The human cranium Is made of ………………bones.

Answer:

1. 7
2. 14
3. Troponin and Tropomyosin
4. Sarcoplasmic reticulum
5. 11 and 12
6. 8

1st PUC Biology Locomotion and Movement Additional Questions and Answers

1st PUC Biology Locomotion and Movement One Mark Questions

Question 1.
Name two sites in our body where ciliary movement is seen.
Answer:
Fallopian tube and trachea.

Question 2.
Give two examples of movements that involve muscular movement.
Answer:
Movement of limbs, jaw, tongue etc.

Question 3.
Why are striated muscles called skeletal muscles?
Answer:
Striated muscles are attached to bones and so-called skeletal muscles.

Question 4.
Mention two sites on our body where striated muscles are present.
Answer:
Limbs and tongue.

Question 5.
Why are smooth muscles called visceral muscles?
Answer:
Smooth muscles are located in the inner walls of hollow visceral organs of the body like the alimentary canal, reproductive tract etc. So they are known as visceral muscles.

Question 6.
Name the connective tissue layer of muscle bundles.
Answer:
Fascia.

Question 7.
Where is ciliary movement mostly seen in our body?
Answer:
Ciliary movement occurs in most of our internal tubular organ which are lined by ciliated epithelium.

Question 8.
Name the three types of muscles in humans.
Answer:
Skeletal, visceral and cardiac.

Question 9.
Name the cells which exhibit amoeboid movement.
Answer:
Macrophages and leucocytes in blood.

Question 10.
What are myofibrils?
Answer:
Large number of parallelly arranged filaments in the sarcoplasm are called myofibrils.

Question 11.
What is the striated appearance of myofibrils due to?
Answer:
Striated appearance of myofibril is due to the distribution pattern of two proteins, actin and myosin.

Question 12.
Name the functional Unit of muscles.
Answer:
Sacromere.

Question 13.
How are action and myosin filaments arranged during the resting state of muscle?
Answer:
In a resting state, the edges of the thin filaments on either side of the thick filaments, partially overlap the free ends of the thick filaments.

Question 14.
What is a H – zone?
Answer:
Central part of the A- band not overlapped by the thin filaments is called H – zone.

Question 15.
Name the protein which is distributed at regular intervals on the tropomyosin.
Answer:
Troponin.

Question 16.
What is the function of troponin?
Answer:
In the resting state a subunit of troponin masks the active binding sites for myosin on the actin filaments

Question 17.
Name the monomers of myosin filament.
Answer:
Meromyosins.

Question 18.
What are the two parts of meromyosins?
Answer:
Meromyosin contains two parts:

• Globular head with a short arm called heavy meromyosin (HMM)
• A tail called Light meromyosin (LMM)

Question 19.
What is a cross arm?
Answer:
The head of meromyosin projects outwards at regular distance and angle from each other from the surface of polymerised myosin filament which is known as cross arm.

Question 20.
What causes fatigue in muscles?
Answer:
Repeated activation of the muscles lead to the accumulation of lactic acid due to anaerobic breakdown of glycogen causing fatigue.

Question 21.
What Is myoglobin?
Answer:
Myoglobin is a red coloured oxygen storing pigment present in muscles.

Question 22.
Name two specialised connective tissues.
Answer:
Bone and cartilage

Question 23.
How many bones does a human being contain ?
Answer:
206 bones.

Question 24.
What salts are present In cartilage?
Answer:
Chondroitin salts.

Question 25.
How many bones does axial skeleton comprise of?
Answer:
80 bones.

Question 26.
What constitute axial skeleton?
Answer:
Skull, vertebral column, sternum and ribs.

Question 27.
Name the two set of bones in the skull.
Answer:
Cranial bones and facial bones.

Question 28.
What are ear ossicles made of?
Answer:
Malleus, Incus and Stapes.

Question 29.
How does skull region articulate with the superior region of the vertebral column?
Answer:
With the help of occipital condyles.

Question 30.
What is vertebral column formed of?
Answer:
Vertebral column is formed by 26 serially arranged units called vertebrae.

Question 31.
What is sternum?
Answer:
Sternum is a flat bone on the ventral midline of thorax.

Question 32.
What is a hyoid?
Answer:
Hyoid is a U- shaped bone present at the base of the buccal cavity.

Question 33.
Why are ribs called bicephalic?
Answer:
Ribs contain two articulation surface on its dorsal end and hence called bicephalic.

Question 34.
Name the major components of appendicular skeleton.
Answer:
The bones of the limbs and their girdles.

Question 35.
Name the longest bone in human body. (All India 2005)
Answer:
Femur (thigh bone)

Question 36.
What is acromion?
Answer:
The dorsal, flat, triangular body of scapula has a spine which projects as a flat, expanded process called the acromion.

Question 37.
What bones help In the articulation of the upper and the lower limbs with the axial skeleton.
Answer:
Pectoral and Pelvic girdle respectively.

Question 38.
What is the technical term for collar bone?
Answer:
Clavicle.

Question 39.
Name the cavity in the pectoral girdle with which head of humerus articulates.
Answer:
Glenoid cavity.

Question 40.
What Is meant by coxal bones?
Answer:
The two halves of the pelvic girdle are called coxal bones.

Question 41.
What is acetabulum in the pelvic girdle?
Answer:
Acetabulum is a cavity at the point of fusion of coxal bones to which the thigh bone articulates.

Question 42.
Name the components of coxal bone.
Answer:
Illium, ischium and pubis.

Question 43.
What are the Joints?
Answer:
Joints are points of contact between bones, or between bones and cartilages.

Question 44.
Name the classification of joints.
Answer:
Fibrous, cartilaginous and synovial.

Question 45.
What are pubic symphysis?
Answer:
Public symphysis is the cartilaginous joint between the two halves of the pelvic girdle on the ventral side.

Question 46.
Which type of joint Is the knee joint?
Answer:
Hinge joint.

Question 47.
How are synovial joints characterised ?
Answer:
Synovial joints are characterised by the presence of a fluid filled synovial cavity between the articulating surfaces of the two bones.

Question 48.
What type of Joint is present between carpal and metacarpal of thumb ?
Answer:
Saddle joint.

Question 49.
What causes gouty arthritis In human ? (All India 2005)
Answer:
lnflammation of joints due to accumulation of uric acid crystals.

1st PUC Biology Locomotion and Movement Two Marks Questions

Question 1.
Mention four special properties of muscles.
Answer:

• Contractility
• Excitability
• Extensibility
• Elasticity

Question 2.
Give two examples of ciliary movement in our body.
Answer:

• The coordinated movements of cilia in the trachea help in removal of dust particles and foreign substances inhaled along with atmospheric air.
• Passage of ova through the female reproductive tract is also facilitated by the ciliary movement.

Question 3.
Differentiate between striated and smooth muscles.
Answer:

Striated	Smooth
(i) These are found attached to the skeletal elements	(i) They are found in the wall of visceral organs.
(ii) Striations are prominent	(ii) Striations are absent
(iii) They are voluntary in functions.	(iii) They are involuntary in function
(iv) Cells are multinucleate	(iv) Cells are uninucleate
(v) They are innervated by voluntary nervous system.	(v) They are innervated by autonomic nervous system

Question 4.
Bring out the differences between cardiac muscles and smooth muscles.
Answer:

Cardiac	Smooth
(i)  They are found only in the wall of the heart. (ii)   Striations are faintly seen (iii)  Cells are cyclindrical and branched (iv)  Intercalated discs are present	(i) They are found in the wall of visceral organs. (ii) Striations are absent (iii) Cells are spindle shaped (iv)  Intercalated discs are absent

Question 5.
What is sarcoplasmic reticulum? What is its function?
Answer:
The endoplasmic reticulum of striated muscle fibres is called sarcoplasmic reticulum. It is the storehouse of calcium ions.

Question 6.
What are A-band and I-band?
Answer:
Each myofibril has alternate dark and light bands on it. The striated appearance of myofibril is due to the distribution pattern of two important proteins – Actin and myosin. The light bands contain actin and is called I-band on isotropic band, whereas the dark band called ‘A1 band or Anisotropic band contains myosin.

Question 7.
Differentiate between bone and cartilage.
Answer:

Bone	Cartilage
(i) It is a hard or rigid connective tissue. (ii) The matrix is deposited with calcium salts. (iii) One osteocyte is found in a lacuna. (iv) Haversian system are present.	(i) It is a semi-rigid connective tissue (ii) The matrix contains chondroitin salts. (iii) 2 to 4 chondrocytes are present in lacuna. (iv) Haversian systems are absent.

Question 8.
What are the two principal divisions of human skeletal system ? How many bones are present in each of them and what do they constitute of ?
Answer:
(i) Axial skeleton

• 80 bones
• constitute of skull, vertebral column,
• sternum and ribs.

(ii) Appendicular skeleton

• 126 bones
• Constitute of bones of the limbs and their girdles.

Question 9.
What are the functions performed by vertebral column ?
Answer:

• It protects the spinal cord;
• It supports the head.
• It serves as the point of attachment for the ribs.
• Provides place for attachment of muscles of the back

Question 10.
Describe the vertebra chondral ribs.
Answer:
The 8th, 9th and 10th pairs of ribs are called vertebra – chondral ribs.
They remain attached dorsally to the respective thoracic vertebrae and ventrally to the sternum through the seventh rib.

Question 11.
Name the bones of palm. How many of them are present in each palm?
Answer:
Bones of palm are called metacarpals. There are five of them in each palm.

Question 12.
Explain a synovial joint Give two examples.
Answer:
Synovial joints are characterised by the presence of a fluid filled synovial cavity between the articulating surfaces of the two bones. Such an arrangement allows considerable movement. These joints help in locomotion and many other movements. Ex: Ball and socket joint, Pivot joint.

Question 13.
Why can red muscle fibres work for a prolonged period, while a white muscle fibre suffers from fatigue soon? (Delhi 2005 C)
Answer:
Red muscle fibres contain a pigment myoglobin which stores oxygen. These muscles also contain plenty of mitochondria which can utilise the large amount of oxygen stored in them for ATP production. Hence they can work for a prolonged period without getting fatigue.

Whereas, white muscle fibres possess very less quantity of myoglobin and very few mitochondria in them. Hence they depend on anaerobic process for energy and get fatigue soon.

Question 14.
What is the role of calcium ions In muscle contraction ? (All India 2004)
Answer:

• Calcium ions bind to specific sites on the troponin component of thin (actin) filaments.
• As a result, conformational change occurs in the troponin molecules and the active sites of F- actin are exposed. These are the sites Specific to myosin head that shows Mg dependent ATP- ase activity.
• When calcium ions are pumped back into the sarcoplasmic reticulum, the troponin component becomes free to mask the active sites for myosin head. This leads to breakage of cross bridges and the actin filaments slide out of A – band.

Question 15.
List any four functions of skeleton in higher animals. (Delhi 1999)
Answer:

• It plays a vital role in movement and locomotion.
• It provides protection to many vital organs.
• It series as reservoir of calcium and phosphates.
• The bone marrow of long bones produces blood cells.

1st PUC Biology Locomotion and Movement Three Marks Questions

Question 1.
Explain giving one example of each, the three types of joints In human skeletons based on the capacity of movement. (Delhi 2006)
Answer:
(i) Immovable / Fibrous joint
The articulating bones are very tightly held with the help of white fibrous connective tissue and there is no space between the bones. Eg: Surtures between skull bones.

(ii) Slightly movable / Cartilaginous joints: The bones involved are joined together with the help of cartilages and allows limited movement. Eg: Joint between adjacent vertebrae in the vertebral column

(iii) Freely movable/synovial joints:
These joints are characterised by the presence of fluid filled synovial cavity between the articulating surfaces of two bones which allows considerable movement. Eg: Ball and socket joint, pivot joint etc.

Question 2.
What are the three types of muscle tissue? Write two characteristic points about the structure of each of them?
Answer:
Three types of muscle tissue are:
(a) Striated muscles

• These are skeletal muscles and are closely associated with the skeletal components of the body.
• Their activities are under the voluntary control of the nervous system.
• They are involved in locomotory actions and changes of body postures.

(b) Visceral muscles:

• They are located in the inner walls of hollow visceral organs like alimentary canal, reproductive tract etc.
• They do not exhibit any striation and are smooth if appearance.
• Their activities are not under the voluntary control of the nervous system.

(c) Cardiac muscles:

• They are the muscles of the heart and are striated.
• Cardiac muscle cells assemble in a branching pattern to form a cardiac muscle.
• They are involuntary in nature.

Question 3.
How many vertebrae In all, do we have? Categorize them on the basis of their location giving the specific number in each category. (Foreign 2004)
Answer:
We have a total of 26 vertebrae in our body.

• Cervical vertebrae (7) in the neck region.
• Thoracic vertebrae (12) present in the thoracic region of the trunk.
• Lumbar vertebrae (5) present in the abdominal region.
• Sacrum (1) is the triangular bone at the end of vertebral column.
  Coccygeal (1) which is vestigial tail bone in human being.

Question 4.
Describe the structure of sarcomere.
Answer:
The portion of the myofibril between two successive ‘z’ lines is called as sarcomere. It is the functional unit of muscle contraction. A sarcomere consists of a dark band in the centre and light bands on either side. The dark band or Anisotropic band (A band) is made of myosin and the light band on Isotropic band (I- band) is made of actin filaments.

Along the centre of the I- band is an elastic fibre called z – line, that bisects the band. Their filaments are attached firmly to the z – line. The myosin filaments are also held together in the centre by a thin fibrous membrane called M – Line. The central part of A band, not over lapped by thin filaments (I- band) is called a H – zone.

Question 5.
Draw a labelled diagram of vertebral column showing different regions.
Answer:

Question 6.
Name the different bones of forelimb and their number in human beings.
Answer:

• Humerus (1)
• Ulna (1)
• Radius (1)
• Carpals (8)
• Metacarpals (5)
• Phalanges (14)

Question 7.
Draw a neat labelled diagram of forelimb indicating all the bones.
Answer:

Question 8.
Name the A different bones of hind limb and their number in human beings.
Answer:

• Femur (1)
• Tibia (1)
• Fibula (1)
• PateNa (1)
• Tarsals (7)
• Metatarsals (5)
• Phalanges (14)

Question 9.
Draw a neat labelled diagram of hind limb indicating ail the bones.
Answer:

1st PUC Biology Locomotion and Movement Five Marks Questions

Question 1.
Explain the sliding filament theory of the mechanism of muscle contraction.
Answer:

Mechanism of muscle contraction is best explained by the sliding filament theory which states that contraction of a muscle fiber takes place by the sliding of the thin filaments over the thick filaments.

‘Muscle Contraction is initiated by a signal sent by the central nervous system (CNS) via a motor neuron. A motor neuron along with the muscle fibres connected to it constitute a motor unit. The junction between a motor neuron and the sarcolemma of the muscle fibre is called the neuromuscular junction or motor – end plate. A neural signal reaching this junction releases a neurotransmitter which generates an action potential in the sacrolemma. This spreads through the muscle fibre and causes the release of calcium ions into the sarcoplasm.

Increase in Ca⁺⁺ level leads to the binding of calcium with a subunit of troponin on actin filaments and thereby remove the masking of active sites for myosin. Utilising the energy from ATP hydrolysis, the myosin head now binds to the exposed active sites on actin filaments towards the centre of ‘A’ band. The Z’ line attached to these actins are also pulled inwards thereby causing a shortening of the sarcomere, i.e contraction. During contraction the T bands get reduced, whereas the ‘A’ bands retain the length.

The ATP is again hydrolysed by the myosin head and the cycle of cross bridge formation and breakage is repeated causing further sliding. The process continues till the Ca⁺⁺ ions are pumped back to the sarcoplasmic Cisternae resulting in the masking of actin filaments. This causes the return of Z lines back to their original position, i.e. relaxation.

Question 2.
Briefly give an account of any five disorders of muscular and skeletal system.
Answer:

• Myasthenia gravis: Auto immune disorder affecting neuro muscular junction leading to fatigue, weakening and paralysis of skeletal muscles.
• Muscular dystrophy: Progressive degeneration of skeletal muscle mostly due to genetic disorder.
• Tetany : Rapid spasms in muscle due to low calcium ions in body fluid.
• Gouty arthritis: Inflammation of joints due to accumulation of uric acid crystals.
• Osteo porosis: Age related disorder characterised by decreasedbdhMfiass and increased chances of fractures. Decreased levels of estrogen is a common cause.

Question 3.
Represent diagrammatically the stages in cross bridge formation, rotation of head and its
Answer:

Question 4.
Draw a neat diagram of human skull labelling any 10 parts.
Answer:

Question 5.
Name different type of synovial Joint giving one example of each type.
Answer:

• Ball and Socket joint. Eg: between humerus and pectoral girdle.
• Hinge joint. Eg: Knee joint and Elbow joint.
• Pivot joint. Eg: between atlas and axis
• Gliding joint. Eg: between the carpals
• Saddle joint Eg: between carpal and metacarpal of thumb.

Question 6.
Draw a neat labelled diagram of
(a) An actin filament
(b) Myosin
Answer: