All or none law is not applicable for

• whole skeletal muscle

• single skeletal muscle fibre

• whole cardiac muscle

• single smooth muscle fibre

212.

Bone is mainly composed of

• iron and phosphorus

• sulphur and calcium

• calcium and phosphorus

• calcium and magnesium

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

• the absence of myofibrils in the central portion of A-band

• the central gap between myosin filaments in the A-band

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

• extension of myosin filaments in the central portion of the A-band

Select the correct statement with respect to locomotion in humans

• A decreased level of progesterone causes osteoporosis in old people

• Accumulation of uric acid crystals in joints causes their inflammation

• The vertebral column has 10 thoracic vertebrae

• The joint between adjacent vertebrae is a fibrous joint

The characteristics and an example of a synovial joint in humans is

• Characteristics	Examples
  Fluid cartilage between two bones, limited movements	Knee joints

• Fluid filled between two joints, provides cushion

  Skull bones

• Fluid filled synovial cavity between two bones

  Joint between atlas and axis

• Lymph filled between two bones, limited movement

  Gliding joint between carpals

The disease that occurs in mature adult human being due to deficiency of calciferol is

• keratomalacia

• osteomalacia

• glossitis

• pernicious anaemia

Which of the following is not involved in muscular contraction?

• Calcium ion

• Troponin

• Actin

• Magnesium ion

What type of cartilaginous tissue is found in the inter-vertebral discs?

• Costal cartilage

• Hyaline cartilage

• White fibrous cartilage

• Yellow elastic cartilage

Osteoid refers to

• the smallest bone of the body

• young hyaline matrix of true bone in which calcium salts are deposited

• membranous ossification of cranium

• the largest bone of the body

Read the following statements.

Statement I. The flat bones of skull are spongy without marrow cavity.

Statement II. Specialised Bones of skull in mammals are called diploic bones.

Identify wheather the given statements are true or false and choose the correct option.

• Statement I	Statement II
  True	False

• False

  True

• True

  True

• False

  False