FREE NEET Biology Practice MCQ Test: Structural Organisation In Animals Exercise 1 Questions Answers With Detailed Explanations [PDF]

Answer: (c)

Nerve cells are highly excitable cells, specialized for impulse conduction. They originate from a neural plate of embryonic ectoderm and serve as structural and functional units of nervous tissue.

Answer: (a)

Answer: (b)

The neuroglial cells are non-excitable cells that protect and support neurons.

Answer: (d)

Answer: (d)

Answer: (d)

Blood glands are present on the 4th, 5th and 6th segments. They produce blood cells and haemoglobin which is dissolved in blood plasma. Blood cells are phagocytic in nature. Lateral hearts are present in 7th and 9th segments and connects dorsal blood vessel with ventral blood vessel. The Nephridia is an organ which occurs in pairs and performs a function similar to the vertebrate kidney. Nephridia remove metabolic wastes from an animal's body.

Answer: (b)

Collagen is an insoluble fibrous protein found extensively in the connective tissue of skin, tendons and bone. Collagen accounts for over 30% of the total body protein of mammals. Globular proteins have compact rounded molecules and are usually water soluble. Lipid is a diverse group of organic compounds, that are insoluble in water but soluble in organic solvents. Carbohydrates are compounds of carbon, hydrogen and oxygen.

Answer: (b)

Answer: (d)

Mast cells secrete histamine are especially prevalent in the connective tissue of skin and respiratory tract and in surrounding blood vessels. Histamine is a vasodilator and lower blood pressure. It is also involved in allergic reactions.

Answer: (c)

Answer: (d)

Mast cells occur in connective tissue proper, these are modified basophils of blood. Mast cells secrete heparin, histamine and serotonin.

Answer: (d)

Answer: (b)

Answer: (a)

Answer: (b)

Answer: (d)

Propelling mucus is the function of simple epithelium.

Answer: (a)

Mast cells are large cells with densely granular cytoplasm that are found in connective tissues. Their granules contain histamine which is a vasodilator, heparin which is an anticoagulant and serotonin which acts as a mediator of inflammation and allergic reactions. Vasopressin is a hormone secreted by the posterior pituitary gland. Calcitonin is a hormone secreted by the thyroid gland. Melanin is a pigment produced by specialized epidermal cells called melanocytes. Relaxin is a hormone produced by the corpus luteum and placenta during the terminal stages of pregnancy.

Answer: (c)

Answer: (b)

Skeletal muscle tissue is closely attached to sketetal bones. In a typical muscle such as the biceps, striated (striped) skeletal muscle fibres are bundled together in a parallel fashion.

Answer: (d)