Locomotion and Movement

15 NEET-UG practice questions on Locomotion and Movement, part of Zoology. The first 15 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
Ca²⁺ released into the sarcoplasm starts muscle contraction by binding to
1. Athe myosin head
2. BG-actin
3. Ctropomyosin
4. Da subunit of troponin
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Answer: D · a subunit of troponin
Increased Ca²⁺ binds a subunit of troponin on the thin filaments. This removes the masking of the active sites on actin, so that myosin heads can bind there.
- A: The myosin head binds ATP and actin, not the Ca²⁺ that starts contraction.
- B: G-actin is the monomer of F-actin and holds the active sites, not the Ca²⁺ binding subunit.
- C: Tropomyosin runs along F-actin and is not the Ca²⁺-binding protein.
Remember this
Ca²⁺ binds troponin; the active sites on actin are unmasked and cross bridges can form.
Question 2 · Easy
Electron micrographs of a relaxed and a contracted sarcomere are compared. Which measurement stays the same in both?
1. ADistance between two Z lines
2. BLength of the I band
3. CLength of the A band
4. DWidth of the H zone
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Answer: C · Length of the A band
Thin filaments slide over thick filaments, and the thick filaments keep their length. The A band therefore keeps its length, while the I bands shorten and the H zone narrows or disappears. The Z lines come closer together.
- A: Z lines move closer because the sarcomere shortens.
- B: The I band shortens as Z lines are drawn inward.
- D: The H zone narrows or disappears as thin filaments move in.
Remember this
Contraction: A band unchanged, I band shorter, H zone narrower or absent, sarcomere shorter.
Question 3 · Medium
Match List-I with List-II. List-I (disorder) A. Myasthenia gravis B. Muscular dystrophy C. Tetany D. Gout List-II (basis) I. Rapid spasms due to low Ca²⁺ in body fluid II. Accumulation of uric acid crystals in joints III. Autoimmune disorder affecting the neuromuscular junction IV. Progressive degeneration of skeletal muscle, mostly genetic
1. AA-IV, B-III, C-I, D-II
2. BA-II, B-IV, C-III, D-I
3. CA-III, B-IV, C-II, D-I
4. DA-III, B-IV, C-I, D-II
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Answer: D · A-III, B-IV, C-I, D-II
Myasthenia gravis is autoimmune and affects the neuromuscular junction. Muscular dystrophy is progressive muscle degeneration, mostly genetic. Tetany follows low Ca²⁺ in body fluid, and gout follows uric acid crystal deposition in joints.
- A: This swaps the two muscle disorders, autoimmune and genetic.
- B: This links myasthenia gravis to uric acid and tetany to the neuromuscular junction.
- C: This swaps the causes of tetany and gout.
Remember this
Myasthenia gravis is autoimmune, muscular dystrophy is genetic, tetany is low Ca²⁺, gout is uric acid crystals.
Question 4 · Medium
Arrange the following events of skeletal muscle contraction in the correct order. A. Ca²⁺ binds troponin and the active sites on actin are unmasked. B. A neural signal at the neuromuscular junction releases acetylcholine. C. Myosin heads form cross bridges and pull actin towards the centre of the A band. D. An action potential spreads through the fibre and Ca²⁺ enters the sarcoplasm. Choose the correct order.
1. AB, A, D, C
2. BB, D, A, C
3. CD, B, A, C
4. DB, D, C, A
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Answer: B · B, D, A, C
Acetylcholine at the neuromuscular junction generates an action potential in the sarcolemma. This spreads through the fibre and releases Ca²⁺ into the sarcoplasm. Ca²⁺ binds troponin to unmask actin's active sites, and only then can myosin heads form cross bridges and pull.
- A: Ca²⁺ cannot bind troponin before the action potential has released it.
- C: The action potential in the fibre comes after acetylcholine is released.
- D: Cross bridges cannot form until the active sites are unmasked.
Remember this
Signal, then acetylcholine, action potential, Ca²⁺, troponin, unmasked sites, cross bridge, sliding.
Question 5 · Easy
Which type of synovial joint is present between the atlas and the axis?
1. APivot joint
2. BGliding joint
3. CSaddle joint
4. DHinge joint
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Answer: A · Pivot joint
NCERT lists the joint between the atlas and the axis as a pivot joint. Synovial joints have a fluid-filled cavity between the articulating surfaces and allow considerable movement.
- B: The gliding joint is the example given between carpals.
- C: The saddle joint is the example given between the carpal and metacarpal of the thumb.
- D: The hinge joint is the example given for the knee.
Remember this
Atlas-axis is pivot; knee is hinge; carpals are gliding; thumb carpal-metacarpal is saddle.
Question 6 · Medium
Given below are two statements: Statement I: Red muscle fibres have a high myoglobin content and plenty of mitochondria, and can be called aerobic muscles. Statement II: White muscle fibres have few mitochondria and much sarcoplasmic reticulum, and depend on anaerobic processes for energy. Choose the correct answer.
1. ABoth Statement I and Statement II are correct
2. BStatement I is correct but Statement II is incorrect
3. CBoth Statement I and Statement II are incorrect
4. DStatement I is incorrect but Statement II is correct
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Question 7 · Medium
Match List-I with List-II. List-I (location) A. Knee B. Humerus and pectoral girdle C. Between carpals D. Carpal and metacarpal of the thumb List-II (synovial joint) I. Saddle joint II. Hinge joint III. Gliding joint IV. Ball and socket joint
1. AA-III, B-IV, C-II, D-I
2. BA-II, B-IV, C-III, D-I
3. CA-IV, B-II, C-III, D-I
4. DA-II, B-IV, C-I, D-III
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Question 8 · Hard
Assertion A: During contraction of a skeletal muscle fibre, the A band keeps its length while the H zone narrows or disappears. Reason R: During contraction, the thick filaments shorten while the thin filaments keep their length. Choose the correct answer.
1. ABoth A and R are correct but R is not the correct explanation of A
2. BBoth A and R are correct and R is the correct explanation of A
3. CA is correct but R is not correct
4. DA is not correct but R is correct
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Question 9 · Hard
In an isolated muscle fibre with Ca²⁺ kept high, the ATP supply runs out just after a power stroke. In what state will the myosin heads remain?
1. ADetached from actin, as tropomyosin masks the sites when ATP is absent
2. BAttached to actin but sliding on, as stored ADP powers more strokes
3. CDetached from actin, as ATP is needed to form the cross bridge
4. DAttached to actin, as a fresh ATP is needed to break the cross bridge
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Question 10 · Hard
A relaxed sarcomere is 2.4 µm long and its A band is 1.6 µm. On contraction the sarcomere shortens to 2.0 µm. What is the total length of light band (both halves together) left within this sarcomere?
1. A0.8 µm
2. B0.2 µm
3. C0.4 µm
4. D0.6 µm
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Question 11 · Medium
Counting the bones of the skull region: cranial bones, facial bones, the hyoid and the ear ossicles of both sides. What total does this give in an adult human?
1. A23
2. B26
3. C22
4. D29
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Question 12 · Easy
Inhaled dust is moved out of the trachea, and ova are carried along the female reproductive tract. Both depend on which type of movement?
1. AMuscular movement
2. BFlagellar movement
3. CCiliary movement
4. DAmoeboid movement
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Question 13 · Medium
Which of the following statements about human ribs are correct? A. Each rib has two articulation surfaces on its dorsal end and is called bicephalic. B. The first seven pairs are connected ventrally to the sternum by hyaline cartilage. C. The 8th, 9th and 10th pairs join the seventh rib through hyaline cartilage. D. The 11th and 12th pairs are connected ventrally to the sternum by hyaline cartilage. Choose the correct answer.
1. AA, B and D only
2. BB and C only
3. CA, B and C only
4. DA, B, C and D
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Question 14 · Medium
Match List-I with List-II. List-I (letter in the figure) A. Letter A B. Letter B C. Letter C D. Letter D List-II (number of bones in an adult human) I. 29 II. 126 III. 24 IV. 26
Figure: MedExams
1. AA-I, B-IV, C-III, D-II
2. BA-I, B-III, C-IV, D-II
3. CA-IV, B-I, C-III, D-II
4. DA-II, B-IV, C-III, D-I
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Question 15 · Medium
Four lengths are marked on a relaxed sarcomere of skeletal muscle. Black bars are thick filaments and blue lines are thin filaments. Which length stays unchanged when the muscle contracts by sliding of filaments?
Figure: MedExams
1. ALength Q
2. BLength P
3. CLength R
4. DLength S
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Locomotion and Movement

Ca²⁺ released into the sarcoplasm starts muscle contraction by binding to

Electron micrographs of a relaxed and a contracted sarcomere are compared. Which measurement stays the same in both?

Which type of synovial joint is present between the atlas and the axis?

Match List-I with List-II. List-I (location) A. Knee B. Humerus and pectoral girdle C. Between carpals D. Carpal and metacarpal of the thumb List-II (synovial joint) I. Saddle joint II. Hinge joint III. Gliding joint IV. Ball and socket joint

Assertion A: During contraction of a skeletal muscle fibre, the A band keeps its length while the H zone narrows or disappears. Reason R: During contraction, the thick filaments shorten while the thin filaments keep their length. Choose the correct answer.

In an isolated muscle fibre with Ca²⁺ kept high, the ATP supply runs out just after a power stroke. In what state will the myosin heads remain?

A relaxed sarcomere is 2.4 µm long and its A band is 1.6 µm. On contraction the sarcomere shortens to 2.0 µm. What is the total length of light band (both halves together) left within this sarcomere?

Counting the bones of the skull region: cranial bones, facial bones, the hyoid and the ear ossicles of both sides. What total does this give in an adult human?

Inhaled dust is moved out of the trachea, and ova are carried along the female reproductive tract. Both depend on which type of movement?

Match List-I with List-II. List-I (letter in the figure) A. Letter A B. Letter B C. Letter C D. Letter D List-II (number of bones in an adult human) I. 29 II. 126 III. 24 IV. 26

Four lengths are marked on a relaxed sarcomere of skeletal muscle. Black bars are thick filaments and blue lines are thin filaments. Which length stays unchanged when the muscle contracts by sliding of filaments?