Spectrum biology

(Axel Boer) #1
(a)A–Fascicle, B–Muscle fibre, C–Sarcolemma, D–Blood
capillary
(b)A–Muscle fibre, B–Fascicle, C–Sarcolemma, D–Blood
capillary
(c)A–Muscle fibre, B–Fascicle, C–Sarcoplasm, D–Blood
capillary
(d)A–Muscle fibre, B–Endoplasmic reticulum, C–Sarcoplasm,
D–Blood capillary

20 .With reference to the structure of muscle, consider
the diagram of thick filament


Given below are few statements regarding the
structure of thick myofilaments.
I.Each myosin is a polymerised protein.
II.Many meromyosin constitutes one thick
filament (myosin)
III.Each meromyosin’s tail is called heavy
meromyosin (HMM) and head is called light
meromyosin (LMM).
IV.The globular head is an active ATPase enzyme
and has binding sites for ATP and active sites
for actin.
Choose the option with correct set of statements.
(a) I, III and IV (b) II and III
(c) I, II and IV (d) I, II, III and IV

21 .Carefully observe the given diagram with reference
to series of events during muscular contraction.


Consider the given statements describing the steps
during the above mentioned process.
I.Myosin head binds to the exposed active site on
actin to form a cross bridge.
II.The Z-line attached to these actin are also
pulled inwards thereby causing shortening of
sarcomere, also called contraction.
III.This pulls the attached actin filaments towards
the centre of A-band.
Arrange the given steps in sequence from first
to last and choose the correct option depicting
it.
(a) I → II → III (b) III → II → I
(c) I → III → II (d) III → I →II

22 .Consider the given diagram and identify the labels
A, B and C.

A B C
(a) Clavicle Costal cartilages Xiphoid process
(b) Costal cartilages Body of sternum Manubrium
(c) Xiphoid process Clavicle Costal cartilages
(d) Manubrium Body of sternum Xiphoid process
23 .Consider the given diagrams in column I and
choose the correct type for each of them from
column II.

Column I Column II

A. (i) Pivot

B. (ii) Saddle

C. (iii) Gliding

D. (iv) Hinge

Choose the correct codes.
A B C D
(a)(i) (iii) (ii) (iv)
(b)(iii) (iv) (i) (ii)
(c)(ii) (iii) (i) (iv)
(d)(iii) (i) (iv) (ii)

Myosin molecules Myosin head

Half I-band One A-band Myosin filament

Z-band

Z-band

Actin
filament

Z M Z

H

T12
L1

A

B

C

RIB 12
RIB 11

Sternum
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