Locomotion and Movement — Page 10 | NEET Biology

Q91

Which of the following is not an autoimmune disease?

A Psoriasis

B Rheumatoid arthritis

C Vitiligo

D Alzheimer's disease

Correct Answer

Option D

Solution

(d) Alzheimer's disease is a neurodegenerative disorder (acetylcholine deficiency), not autoimmune.

Q92

Which of the following muscular disorders is inherited?

A Tetany

B Muscular dystrophy

C Myasthenia gravis

D Botulism

Correct Answer

Option B

Solution

(b) Muscular dystrophy is an inherited disease causing progressive muscle weakening.

Q93

Which of the following diseases is an autoimmune disorder?

A Gout

B Myasthenia gravis

C Arthritis

D Osteoporosis

Correct Answer

Option B

Solution

(b) Myasthenia gravis is autoimmune disorder affecting the neuromuscular junction, causing fatigue and paralysis.

Q94

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

A Calcitonin and thymosin - Thyroid hormones

B Pepsin and prolactin - Two digestive enzymes secreted in stomach

C Troponin and myosin - Complex proteins in striated muscles

D Secretin and rhodopsin - Polypeptide hormones

Correct Answer

Option C

Solution

(c) Troponin (on actin filaments) and myosin are both complex proteins in striated muscles.

Q95

During muscle contraction in humans the

A Actin filaments shorten

B Sarcomere does not shorten

C A band remain same

D A, H and I bands shorten

Correct Answer

Option C

Solution

(c) During contraction I-bands shorten, A-band retains its length, H-zone narrows.

Q96

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

A The central gap between myosin filaments in the A-band.

B The central gap between actin filaments extending through myosin filaments in the A-band

C Extension of myosin filaments in the central portion of the A-band.

D The absence of myofibrils in the central portion of A-band.

Correct Answer

Option B

Solution

(b) H-zone (Hensen's Line) is the central part of thick filament not overlapped by thin filaments.

Q97

Sliding filament theory can be best explained as:

A Actin and Myosin filaments shorten and slide pass each other

B Actin and Myosin filaments do not shorten but rather slide pass each other

C When myofilaments slide pass each other, Myosin filaments shorten while Actin filaments do not shorten

D When myofilaments slide pass each other Actin filaments shorten while Myosin filament do not shorten

Correct Answer

Option B

Solution

(b) Sliding filament theory: Actin and Myosin filaments do not shorten but slide past each other.

Q98

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

A Spasm

B Fatigue

C Tetanus

D Tonus

Correct Answer

Option C

Solution

(c) Sustained contraction with no relaxation phase is called muscle tetanus.