Assertion    :       Muscle fibres are said to be contractile in nature.

 Reason      :       Cells of muscle tissues can shorten forcefully and again return to the relaxed state.

Assertion   :       Intercalated discs are important regions of cardiac muscle cells.

Reason      :       Intercalated discs function as boosters for muscle contraction waves.

Assertion   :       Neurons are said to possess the property of excitability.

Reason      :       Neurons can get excited by a given stimulus.

Assertion   :       Ciliated epithelium helps in movement of particles.

Reason      :       Cilia help in movement.

Assertion   :       Columnar epithelium lining the intestinal mucosa appears to have a brush like appearance.

Reason      :       A large number of microvilli are present on brush bordered columnar epithelium.

Assertion             :       Specialization of cells is advantageous for the organism.

Reason                :       It increase the operational efficiency of an organism.

Assertion   :       Mast cells in the human body release excessive amounts of inflammatory chemicals which cause allergic reactions.

Reason      :       Allergens in the environment on reaching human body stimulate mast cells in certain individuals.