Locomotion and Movement · Question 20

During muscular contraction which of the following events occur? Choose the correct answer from the options given below.

1. B, D, E and A only
2. A, C, D and E only
3. A, B, C and D only
4. B, C, D and E only

Match the following columns and select the correct option.

1. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
2. (a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)
3. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
4. (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)

Select the correct option :

1. Each rib is a flat thin bone and all the ribs are connected dorsally to the thoracic vertebrae and ventrally to the sternum
2. There are seven pairs of vertebrosternal, three pairs of vertebrochondral and two pairs of vertebral ribs
3. 8th, 9th and 10th pairs of ribs articulate directly with the sternum
4. 11th and 12th pairs of ribs are connected to the sternum with the help of hyaline cartilage.

Which of the following muscular disorders is inherited?

1. Myasthenia gravis
2. Botulism
3. Tetany
4. Muscular dystrophy

Calcium is important in skeletal muscle contraction because it

1. detaches the myosin head from the actin filament
2. binds to troponin to remove the masking of active sites on actin for myosin
3. prevents the formation of bonds between the myosin cross bridges and the actin filament
4. activates the myosin ATPase by binding to it

Which of the following hormones can play a significant role in osteoporosis?

1. Estrogen and parathyroid hormone
2. Aldosterone and prolactin
3. Progesterone and aldosterone
4. Parathyroid hormone and prolactin

The pivot joint between atlas and axis is a type of

1. cartilaginous joint
2. synovial joint
3. saddle joint
4. fibrous joint.

Out of 'X' pairs of ribs in humans only 'Y' pairs are true ribs. Select the option that correctly represents values of X and Y and provides their explanation.

1. X = 12, Y = 5; True ribs are attached dorsally to vertebral column and sternum on the two ends
2. X = 24, Y = 2; The true ribs are dorsally attached to vertebral column but are free on ventral side
3. X = 24, Y = 12; True ribs are dorsally attached to vertebral column but are free on ventral side
4. X = 12, Y = 7; True ribs are attached dorsally to vertebral column and ventrally to the sternum

Lack of relaxation between successive stimuli in sustained muscle contraction is known as

1. tetanus
2. tonus
3. spasm
4. fatigue.

Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction.

1. Calcium
2. Magnesium
3. Sodium
4. Potassium