Assertion   :       Thigh muscles can get tired but not the muscles of ventricle of heart.

Reason      :       Muscles of thigh are voluntary whereas that of heart are involuntary muscles.

Assertion   :       Smooth muscle fibres do not appear to be striated.

Reason      :       This is due to regular alternate arrangement of thick and thin filaments is smooth muscle fibre.

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

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

Assertion   :       Presence of connective tissue inside the brain is essential for conduction of nerve impulse.

Reason      :       Connective tissue hold together the nerve cells of brain.

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

Reason      :       Neurons can get excited by a given stimulus.

Assertion   :       Non-myelinated nerve fibres do not possess nodes of Ranvier.

Reason      :       This is due to the absence of nissl’s bodies in node of Ranvier.

Assertion   :       Extracellular materials help in separation of cells.

Reason      :       Cell junctions are formed by extra cellular materials.

Assertion   :       Epithelial tissues protect the under lying and over lying tissues.

Reason      :       Materials are exchanged at the surfaces across the epithelial tissues.

Assertion   :       The cells of columnar epithelium in absorptive surfaces often bears microvilli on their free ends.

Reason      :       Microvilli on their free ends.

Assertion   :       Ciliated epithelium helps in movement of particles.

Reason      :       Cilia help in movement.

Assertion   :       Fibroblasts help in protection.

Reason      :       Fibroblasts synthesize two kinds of protein which are protective in nature.

Assertion   :       Pinna of ear is elastic in nature.

Reason      :       Hyaline cartilage present in pinna.

Assertion   :       Lining of some hollow organs & cavities are moist.

Reason      :       This is because of the mucus secreted by the connective tissue.

Assertion   :       Extracellular materials are important for cells.

Reason      :       Intercellular materials surround the cells & bind them together.

Assertion   :       Simple epithelium covers surfaces exposed to mechanical or chemical abrasions.

Reason      :       Protection of underlying tissues is the major function of simple epithelium.

Assertion   :       Materials are exchanged between epithelial & connective tissue by diffusion.

Reason      :       Blood vessels are absent in epithelial tissue.

Assertion   :       Urinary bladder can considerably expand to accommodate urine.

Reason      :       It is lined by stretchable squamous epithelium.

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   :    Pseudostratified ciliated columnar epithelium is present in the inner lining of trachea.

Reason      :    Ciliary movements propel the mucus & foreign particles towards the larynx.

Brain of cockroach supplies nerves to

Haemolymph in cockroach is devoid of

Assertion   :       Mast cells help in body defence.

Reason      :       Mast cells phagocytose & destroy microbes.

Assertion   :       Surface of skin is impervious to water.

Reason      :       Surface of skin is covered by stratified cuboidal epithelium.

Assertion   :       Bones possess longitudinal canals called lacunae.

Reason      :       Lacunae carry blood vessels & nerves to the bones.

Assertion   :     Cartilage (protein matrix) and bone (calcium matrix) are rigid connective tissue.

Reason      :     Blood is connective tissue in which plasma is the matrix.

Assertion             :       Specialization of cells is advantageous for the organism.

Reason                :       It increase the operational efficiency of an organism.

Assertion   :       Histamine is related with allergic and inflammatory reactions.

Reason      :       Histamine is a vasodilator.

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.

Embryologically, the body of cockroach is formed of 20 segments. What is the number in each region?

Presence of anal styles distinguishes male cockroach from the female. It is present on :