Question

Write the difference between:
(a) Actin and Myosin
(b) Red and White muscles
(c) Pectoral and Pelvic girdle

Answer 1

(a) Actin and Myosin

| ** Actin**| | ** Myosin**
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1| Actin is a thin contractile protein.| 1| Myosin is a thick contractile protein.
2| It is present in light bands and is called an isotropic band.| 2| It is present in dark bands and is called an anisotropic band.

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(b) Red and White muscles

** Red muscle fibre**	** White muscle fibre**
1	Red muscle fibres are thin and smaller in size.
2	They are red in colour as they contain large amounts of myoglobin.
3	They contain numerous mitochondria.
4	They carry out slow and sustained contractions for a long period.
5	They provide energy by aerobic respiration.

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(c) Pectoral and Pelvic girdle

Pectoral girdle	**Pelvic girdle **
1	It is a skeletal support from where the forelimbs of vertebrates are attached.
2	It is composed of two Bones namely, clavicle or collar bones and scapula or shoulder bone.