Chapter 17: Locomotion and Movement Assertion-Reason Questions | biology Class 11 CBSE

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 1

Logic Check

Assertion (A): All locomotions are movements, but not all movements are locomotions. Reason (R): Locomotion specifically refers to a voluntary movement that results in a change of place or location, whereas movement is a broader term including any change in position.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 2

Logic Check

Assertion (A): Skeletal muscles are called voluntary muscles. Reason (R): Skeletal muscles are located in the walls of hollow visceral organs and are under the control of the autonomic nervous system.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 3

Logic Check

Assertion (A): The I band of a sarcomere shortens during muscle contraction. Reason (R): During contraction, thin actin filaments slide towards the centre of the A band, reducing the length of the region containing only thin filaments.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 4

Logic Check

Assertion (A): The A band retains its original length during muscle contraction. Reason (R): The thick myosin filaments that constitute the A band do not shorten or move during contraction — only the thin actin filaments slide over them.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 5

Logic Check

Assertion (A): Sarcoplasmic reticulum is the storehouse of calcium ions in a muscle fibre. Reason (R): Release of calcium from the sarcoplasmic reticulum is required to unmask the active sites on actin for myosin binding.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 6

Logic Check

Assertion (A): Cardiac muscles are both striated and involuntary. Reason (R): Cardiac muscles are striated because of their organised actin-myosin arrangement, and involuntary because the nervous system does not directly control their activities.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 7

Logic Check

Assertion (A): The H zone disappears during maximum muscle contraction. Reason (R): The H zone represents the central region of the A band not overlapped by thin filaments at rest; at maximum contraction, thin filaments from both sides completely cover this region.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 8

Logic Check

Assertion (A): Troponin in the resting state prevents muscle contraction. Reason (R): A subunit of troponin masks the active binding sites for myosin on the actin filaments, preventing cross bridge formation.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 9

Logic Check

Assertion (A): Red muscle fibres are suited for prolonged, sustained activity. Reason (R): Red fibres contain high amounts of myoglobin and many mitochondria, enabling aerobic ATP production for sustained energy supply.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 10

Logic Check

Assertion (A): White muscle fibres contain a high amount of sarcoplasmic reticulum. Reason (R): White fibres depend on aerobic respiration and require extensive calcium storage for sustained activity.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 11

Logic Check

Assertion (A): The human skull is described as dicondylic. Reason (R): The skull articulates with the vertebral column via two occipital condyles.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 12

Logic Check

Assertion (A): The vertebral column is composed of 33 individual vertebrae. Reason (R): The human vertebral column has 26 serially arranged units because the sacral vertebrae fuse into one and the coccygeal vertebrae fuse into one.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 13

Logic Check

Assertion (A): The first seven pairs of ribs are called true ribs. Reason (R): True ribs are directly connected to the sternum ventrally via hyaline cartilage.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 14

Logic Check

Assertion (A): Floating ribs are the 11th and 12th pairs of ribs. Reason (R): Floating ribs are not connected ventrally to either the sternum or the 7th rib, only being attached dorsally to thoracic vertebrae.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 15

Logic Check

Assertion (A): The scapula is a triangular flat bone located on the ventral part of the thorax. Reason (R): The scapula is situated in the dorsal part of the thorax between the second and seventh ribs.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 16

Logic Check

Assertion (A): The glenoid cavity of the scapula forms the shoulder joint with the humerus. Reason (R): The glenoid cavity is a depression below the acromion of the scapula, and the shoulder joint formed is a ball and socket synovial joint.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 17

Logic Check

Assertion (A): The pubic symphysis between the two halves of the pelvic girdle is a synovial joint. Reason (R): The pubic symphysis contains fibrous cartilage, making it a cartilaginous joint that permits very limited movement.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 18

Logic Check

Assertion (A): Fibrous joints allow no movement between the bones they connect. Reason (R): Fibrous joints are connected by dense fibrous connective tissue in the form of sutures, which do not permit any mobility.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 19

Logic Check

Assertion (A): Synovial joints allow the greatest range of movement among the three types of joints. Reason (R): Synovial joints have a fluid-filled synovial cavity between the articulating surfaces, reducing friction and enabling considerable movement.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 20

Logic Check

Assertion (A): The knee joint is an example of a pivot joint. Reason (R): The knee joint is a hinge joint that allows movement primarily in one plane — flexion and extension of the leg.

Reasoning Options

ByteNotes

Chapter sections

Chapter 17: Locomotion and Movement | Assertion-Reason

Assertion (A): All locomotions are movements, but not all movements are locomotions. Reason (R): Locomotion specifically refers to a voluntary movement that results in a change of place or location, whereas movement is a broader term including any change in position.

Assertion (A): Skeletal muscles are called voluntary muscles. Reason (R): Skeletal muscles are located in the walls of hollow visceral organs and are under the control of the autonomic nervous system.

Assertion (A): The I band of a sarcomere shortens during muscle contraction. Reason (R): During contraction, thin actin filaments slide towards the centre of the A band, reducing the length of the region containing only thin filaments.

Assertion (A): The A band retains its original length during muscle contraction. Reason (R): The thick myosin filaments that constitute the A band do not shorten or move during contraction — only the thin actin filaments slide over them.

Assertion (A): Sarcoplasmic reticulum is the storehouse of calcium ions in a muscle fibre. Reason (R): Release of calcium from the sarcoplasmic reticulum is required to unmask the active sites on actin for myosin binding.

Assertion (A): Cardiac muscles are both striated and involuntary. Reason (R): Cardiac muscles are striated because of their organised actin-myosin arrangement, and involuntary because the nervous system does not directly control their activities.

Assertion (A): The H zone disappears during maximum muscle contraction. Reason (R): The H zone represents the central region of the A band not overlapped by thin filaments at rest; at maximum contraction, thin filaments from both sides completely cover this region.

Assertion (A): Troponin in the resting state prevents muscle contraction. Reason (R): A subunit of troponin masks the active binding sites for myosin on the actin filaments, preventing cross bridge formation.

Assertion (A): Red muscle fibres are suited for prolonged, sustained activity. Reason (R): Red fibres contain high amounts of myoglobin and many mitochondria, enabling aerobic ATP production for sustained energy supply.

Assertion (A): White muscle fibres contain a high amount of sarcoplasmic reticulum. Reason (R): White fibres depend on aerobic respiration and require extensive calcium storage for sustained activity.

Assertion (A): The human skull is described as dicondylic. Reason (R): The skull articulates with the vertebral column via two occipital condyles.

Assertion (A): The vertebral column is composed of 33 individual vertebrae. Reason (R): The human vertebral column has 26 serially arranged units because the sacral vertebrae fuse into one and the coccygeal vertebrae fuse into one.

Assertion (A): The first seven pairs of ribs are called true ribs. Reason (R): True ribs are directly connected to the sternum ventrally via hyaline cartilage.

Assertion (A): Floating ribs are the 11th and 12th pairs of ribs. Reason (R): Floating ribs are not connected ventrally to either the sternum or the 7th rib, only being attached dorsally to thoracic vertebrae.

Assertion (A): The scapula is a triangular flat bone located on the ventral part of the thorax. Reason (R): The scapula is situated in the dorsal part of the thorax between the second and seventh ribs.

Assertion (A): The glenoid cavity of the scapula forms the shoulder joint with the humerus. Reason (R): The glenoid cavity is a depression below the acromion of the scapula, and the shoulder joint formed is a ball and socket synovial joint.

Assertion (A): The pubic symphysis between the two halves of the pelvic girdle is a synovial joint. Reason (R): The pubic symphysis contains fibrous cartilage, making it a cartilaginous joint that permits very limited movement.

Assertion (A): Fibrous joints allow no movement between the bones they connect. Reason (R): Fibrous joints are connected by dense fibrous connective tissue in the form of sutures, which do not permit any mobility.

Assertion (A): Synovial joints allow the greatest range of movement among the three types of joints. Reason (R): Synovial joints have a fluid-filled synovial cavity between the articulating surfaces, reducing friction and enabling considerable movement.

Assertion (A): The knee joint is an example of a pivot joint. Reason (R): The knee joint is a hinge joint that allows movement primarily in one plane — flexion and extension of the leg.

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