NEET Biology: Locomotion and Movement questions with solutions

Q1. Salivary glands of cockroach open on

1. Maxilla
2. Hypopharynx
3. Labium
4. Labrum

Answer: Labium

In cockroach, the salivary glands discharge through a common salivary duct into the salivarium at the base of the hypopharynx, which is associated with the labium region in standard exam descriptions. Hence the opening is taken as on the labium among the given options.

Q2. Identify the joints, which are freely movable.

1. Fibrous joints
2. Symphyses
3. synovial joints
4. Cartilaginous joints

Answer: synovial joints

Synovial joints are freely movable because they have a joint cavity, articular cartilage, and synovial fluid that reduce friction and allow wide movement. Fibrous and cartilaginous joints are generally immovable or only slightly movable.

Q3. Select the correct statement regarding the specific disorder of muscular or skeletal system:

1. Muscular dystrophy - age related shortening or muscles.
2. Osteoporosis - decrease in bone mass and higher chance of fractures with advancing age.
3. Myasthenia gravis - Auto immune disorder which inhibits sliding of myosin filaments.
4. Gout - inflammation of joints due to extra deposition of calcium.

Answer: Osteoporosis - decrease in bone mass and higher chance of fractures with advancing age.

Osteoporosis is characterized by reduced bone mass and deterioration of bone tissue, which increases fracture risk, especially with advancing age. The other options describe incorrect mechanisms or causes for their disorders.

Q4. The cervical vertebrae in humans is

1. same as in whale
2. more than that in rabbit
3. double than that of horse
4. less than that in giraffe

Answer: same as in whale

Humans and whales both have 7 cervical vertebrae, so they are the same. This is a common mammalian pattern, despite differences in neck length.

Q5. The type of muscles present in our :

1. heart are involuntary and unstriated smooth muscles
2. intestine are striated and involuntary
3. thigh are striated and voluntary
4. upper arm are smooth muscle fibres fusiform in shape

Answer: thigh are striated and voluntary

Thigh muscles are skeletal muscles, which are striated and under voluntary control. They move the leg, so the correct option is the one describing them as striated and voluntary.

Q6. Formation of cartilage bones involves

1. deposition of bony matter by osteoblasts and resorption by chondroblasts
2. deposition of bony matter by osteoclasts and resorption by chondroblasts
3. deposition of bony matter by osteoclasts only
4. deposition of bony matter by osteoblasts only

Answer: deposition of bony matter by osteoblasts only

Osteoblasts are the cells responsible for forming bone by depositing bony matrix. Osteoclasts resorb bone, and chondroblasts form cartilage, so the correct process is deposition by osteoblasts only.

Q7. Which of the following is not exclusively supplied with involuntary muscles?

1. Muscular coats of blood vessels
2. Muscles of the ducts of glands
3. Muscles of iris
4. Muscles of urethra

Answer: Muscles of urethra

The muscular coats of blood vessels, gland ducts, and the iris are made of involuntary smooth muscle. The urethra is not exclusively supplied by involuntary muscle because its sphincter region includes voluntary control.

Q8. Calcium is important in skeletal muscle contraction because it

1. Binds to troponin to remove the masking of active sites on actin for myosin.
2. Activates the myosin ATPase by binding to it.
3. Prevents the formation of bonds between the myosin cross bridges and the actin filament.
4. Detaches the myosin head from the actin filament.

Answer: Binds to troponin to remove the masking of active sites on actin for myosin.

Calcium binds to troponin, which shifts tropomyosin away from actin’s myosin-binding sites. This exposes the active sites so myosin can form cross-bridges and contraction can proceed.

Q9. Lack of relaxation between successive stimuli in sustained muscle contraction is known as

1. Spasm
2. Fatigue
3. Tetanus
4. Tonus

Answer: Tetanus

Tetanus is the sustained contraction that occurs when successive stimuli arrive so rapidly that the muscle does not fully relax between them. This produces a continuous, fused contraction rather than separate twitches.

Q10. The H-zone in the skeletal muscle fibre is due to:

1. The central gap between myosin filaments in the A-band.
2. The central gap between actin filaments extending through myosin filaments in the A-band.
3. Extension of myosin filaments in the central portion of the A-band.
4. The absence of myofibrils in the central portion of A-band.

Answer: The central gap between actin filaments extending through myosin filaments in the A-band.

The H-zone is the central lighter region of the A-band where thin actin filaments do not overlap the thick myosin filaments. Because only myosin is present there, it appears less dense than the surrounding overlap region.

Q11. During muscle contraction in humans the

1. Actin filaments shorten
2. Sarcomere does not shorten
3. A band remain same
4. A, H and I bands shorten

Answer: A band remain same

In muscle contraction, actin and myosin slide past each other without changing their own lengths. The A band corresponds to the length of the thick myosin filaments, so it stays the same while the I band and H zone shorten.

Q12. Which one of the following pairs of chemical substances is correctly categorized?

1. Calcitonin and thyroxin - Thyroid hormones
2. Pepsin and prolactin - Two digestive enzymes secreted in stomach
3. Troponin and myosin - Complex proteins in striated muscles
4. Secretin and rhodopsin - Polypeptide hormones

Answer: Troponin and myosin - Complex proteins in striated muscles

Troponin and myosin are both protein components of striated muscle involved in contraction. The other pairs mix incorrect categories: calcitonin is not a thyroid hormone pair with thyroxin in the intended sense, pepsin is a stomach enzyme but prolactin is a pituitary hormone, and secretin is a peptide hormone while rhodopsin is a visual pigment.

Q13. What is sarcomere?

1. Part between two H-lines
2. Part between two A-lines
3. Part between two I-bands
4. Part between two Z-lines

Answer: Part between two Z-lines

A sarcomere is the basic contractile unit of striated muscle, extending from one Z-line (Z-disc) to the next. Z-lines mark the boundaries of each repeating segment within a myofibril.

Q14. Which statement is correct for muscle contraction?

1. Length of H-line decreases
2. Length of A-band remains constant
3. Length of I-band increases
4. Length of two Z-lines increases

Answer: Length of A-band remains constant

The A-band corresponds to the length of the thick (myosin) filaments, which does not change during contraction. As actin slides inward, the I-band and H-zone shorten, but the A-band remains constant.

Q15. Which ion is essential for muscle contraction?

1. Na
2. K
3. Ca
4. Cl

Answer: Ca

Calcium ions are required to initiate muscle contraction by binding to troponin, which shifts tropomyosin and exposes actin-binding sites. Without Ca, myosin cannot effectively interact with actin to produce contraction.

Q16. Which of the following is the contractile protein of a muscle?

1. Myosin
2. Tropomyosin
3. Actin
4. Tubulin

Answer: Myosin

Myosin is the main motor protein responsible for contraction in muscle; it uses ATP to pull actin filaments and generate force. Tropomyosin is regulatory, actin is a filament partner, and tubulin is a microtubule protein.

Q17. Sliding filament theory can be best explained as:

1. Actin and Myosin filaments shorten and slide past each other
2. Actin and Myosin filaments do not shorten but rather slide past each other
3. When myofilaments slide pass each other, Myosin filaments shorten while Actin filaments do not shorten
4. When myofilaments slide pass each other Actin filaments shorten while Myosin filament do not shorten

Answer: Actin and Myosin filaments do not shorten but rather slide past each other

In sliding filament theory, actin and myosin keep their own lengths; contraction happens as they slide past each other, increasing overlap. The sarcomere shortens, but the filaments themselves do not.

Q18. Match the following columns and select the correct option.

1. Floating Ribs - Located between second and seventh ribs
2. Acromion - Head of the Humerus
3. Scapula - Clavicle
4. Glenoid cavity - Do not connect with the sternum

Answer: Glenoid cavity - Do not connect with the sternum

The glenoid cavity is the socket on the scapula that articulates with the head of the humerus, so it cannot match with “do not connect with the sternum.” That description belongs to floating ribs, not the glenoid cavity.

Q19. Match the following joints with the bones involved:

1. (a)-(i), (B)-(iii), (C)-(ii), (D)-(iv)
2. (a)-(iii), (B)-(iv), (C)-(ii), (D)-(i)
3. (a)-(iv), (B)-(i), (C)-(ii), (D)-(iii)
4. (a)-(iv), (B)-(ii), (C)-(iii), (D)-(i)

Answer: (a)-(iv), (B)-(ii), (C)-(iii), (D)-(i)

The correct option matches each joint label to the specific bones that form that articulation. Once the bones are identified for each joint, only one option preserves all four pairings correctly.

Q20. The pivot joint between atlas and axis is a type of:

1. Cartilaginous joint
2. Synovial joint
3. Saddle joint
4. Fibrous joint

Answer: Synovial joint

The pivot joint between the atlas and axis is an atlanto-axial joint, which is a synovial joint. It permits rotation of the head around the dens of the axis, and synovial joints are characterized by a joint cavity and free movement.