Muscles exam pack

1


(i) All three types of muscle in a mammal's body contribute to the ‘fight or flight’ response.


Complete the table below by filling in the blank boxes.


Organ Type of muscle Action of muscle in fight or flight
response
heart increases pulse rate
leg muscle
arteriole to liver smooth



[3]

(ii) Muscles in a mammal's leg are made up of units.


The figure is a diagram of one unit.




The thick lines in the A band represent a protein.


Name this protein.

[1]




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, 2 The image below is a transmission electron micrograph of a section of skeletal muscle.




Which row, A to D, shows the correct labels?


Organelle T Region U Region V Region between X and
Y
A Golgi body I-line actin Z-band
B mitochondrion Z-line myofibril sarcomere
C sarcoplasmic reticulum A-band collagen I-band
D mitochondrion I-band myosin sarcoplasmic reticulum



Your answer

[1]




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, 3 The contraction and relaxation of human muscles relies on interactions between different proteins within muscle
cells.


In skeletal muscles, the proteins are arranged in bundles known as myofibrils.


Fig. 4.1 shows simplified diagrams of some of the proteins present in muscle myofibrils.




Fig. 4.1



Using the letters A, B or C, identify the following proteins on Fig. 4.1.


tropomyosin _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _


troponin _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[2]




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