Read the following statements:

(i) Joints are points of contact between bones or between bones and cartilages.
(ii) Force generated by muscles is used to carry out movement through joints, where muscles act as fulcrum.
(iii) Fibrous joints do not allow any movement.

(iv) In cartilaginous joints, the bones involved are joined together with the help of dense fibrous connective tissue.
(v) Synovial joints are characterized by the presence of a fluid filled synovial cavity between the articulating surfaces of the two bones.

Which of the above statements are incorrect?

Given below is diagrammatic representation of an actin filament (thin filament) with labelled parts A, B and C. Which of the following are correct matches with respect to labelled parts and their description?

Read the following statements and choose the correct option:

(i) During muscle contraction, chemical energy is converted into mechanical energy.
(ii) Both actin and myosin are present in A-band.
(iii) Only myosin is present in H-zone.
(iv) Muscular tissue is endodermal in origin.

Read the following statements and choose the correct option:

Statement I: During contraction of skeletal muscles, calcium binds with troponin so that myosin head binding sites on actin are exposed.

Statement II: The process of muscle contraction continues till sodium ions are pumped back to sarcoplasmic reticulum, resulting in masking of actin filaments which results in the return of Z-lines back to their original position.

Whicb of the following statements are false:

(i) Sarcomere is the length of muscle between two Z-lines.
(ii) All or none principle is also called Bowditch law.
(iii) Tropomyosin is the monomer unit of myosin.
(iv) Myosin head has binding sites for troponin and ATP.