Question No:1

Ciliary muscles are found in

[A] Diaphragm of a mammal
[B] Eyes of vertebrates
[C] Heart of vertebrates
[D] Stomach of frog



Question No:2

Inter costal muscles are found in

[A] Fingers
[B] Thoracic ribs
[C] Femur
[D] Radius-ulna



Question No:3

The special contractile protein act in is found in

[A] thick filaments of A-bands
[B] thin filaments of I-bands
[C] both thick and thin bands
[D] whole of myofibril



Question No:4

Striped muscles have

[A] one nucleus
[B] many nuclei
[C] two nuclei
[D] no nuclei



Question No:5

Contractile fibrils of muscles are called

[A] neurofibrils
[B] collagen fibres
[C] myofibrils
[D] elastin



Question No:6

Myofibrils show alternate dark and light bands in

[A] Cardiac muscles
[B] Smooth muscles
[C] Skeletal muscles
[D] both (a) and (c)



Question No:7

Select the correct statement:

[A] A-band is made up of thick myosin filament
[B] H-zone is present hi the middle of A-band
[C] Actin and myosin are polymerized protein with contractility
[D] All



Question No:8

Match the columns:
Column I—- Column II
(A) Inflammation of joints – (1) H-zone
(B) Protein of thick filament – (2) Myosin
(C) Protein of thin filament – (3) Actin
(D) The central part of thick filament not – (4) Arthritis
overlapped by thin filament

[A] A-1,B-2,C-3,D-4
[B] A-1,B-3,C-2,D-4
[C] A-4,B-1,C-2, D-3
[D] A-4, B-2, C-3, D-1



Question No:9

Which of the following statements about the striated muscles is false?
1) Thick filaments hi the ‘A’ band are also held together in the middle of this band by a thin fibrous membrane called ‘M’ line.
2) In the centre of each T band is an elastic fibre called ‘Z’ line which bisects it.
3) The thin filaments are firmly attached to the ‘Z’ line.
4) This central part of thick filament, not overlapped by thin filaments is called the ‘H’ zone,

[A] All
[B] only 2
[C] 1 and 4 only
[D] None



Question No:10

Which of the following statements about the molecular arrangement of actin in myofibrils is incorrect?
1) Each actin (thin) filament is made of two ‘F’ (filamentous) actins helically wound to each other.
2) Each ‘F’ actin is a polymer of monomeric ‘G’ (Globular) actins.
3) Two filaments of another protein, tropomyosin also run close to the ‘F’ actins throughout its length.
4) A complex protein Troponin is distributed at regular intervals on the tropomyosin.

[A] 1, 2 only
[B] 3 only
[C] only 4
[D] None



Question No:11

Mechanism of muscle contraction is best explained by

[A] all or no law
[B] sliding filament theory
[C] Blackman’s law
[D] all



Question No:12

ATP provides energy for muscle contraction by allowing for

[A] an action potential formation in his muscle cell
[B] cross-bridge detachment of myosin from actin
[C] cross-bridge attachment of myosin to actin
[D] release of Ca²⁺ from Sarcoplasmic reticulum



Question No:13

A motor unit is best described as

[A] all the nerve fibres and muscle fibres in a single muscle bundle
[B] one muscle fibres and its single nerve fibre
[C] a single motor neuron and all the muscle fibres that it innervates
[D] as the neuron which carries the message from muscle to CNS



Question No:14

Motor end plate is a

[A] neuromuscular junction
[B] plate of motor neuron
[C] dendron of motor neuron
[D] gradient of protein motive force



Question No:15

During muscle contraction,

[A] chemical energy is changed into electrical energy
[B] chemical energy is changed into mechanical energy
[C] chemical energy is changed into physical energy
[D] mechanical energy is changed into chemical energy