ZOO301 Final Term Solved Paper

Q. Transport system in vertebrates?

• Vertebrates have a closed circulatory system in which the blood never leaves the blood vessels.
• Blood moves from the heart, through arteries, arterioles, capillaries, venules, veins, and back to the heart.
• Exchange between the blood and extracellular fluid only occurs at the capillary level.
• The heart is the center to the circulatory system that circulates the blood throughout the body.
• The coordination of the circulatory system and the respiratory system to ensure proper gas exchange is very important in animals that have lungs and gills.

Q. Define Arteries?

• Arteries are elastic blood vessels that carry blood away from the heart to the organs and tissues of the body.
• The central canal of an artery (and of all blood vessels) is a lumen.

Q. Define veins?

• Veins are relatively inelastic and the wall of a vein contains the same three layers (tunicae) as arterial walls, but the middle layer is much thinner.
• One or more valves are present which permit blood flow only in one direction.

Q. Define capillaries?

• Capillaries are generally composed of a single layer of endothelial cells and are the most numerous blood vessels in an animal’s body.
• Capillaries make an enormous surface area available for the exchange of gases, fluids, nutrients, and wastes between the blood and nearby cells.

Q. What is First line of defense?

First line of defense is external. It includes

• Skin
• Mucous membranes and their secretions.

Q. What is Second line of defense?

Second line of defense is internal. It includes

• Phagocytic WBCs
• Antimicrobial proteins
• Inflammatory response

Q. Write the process of Exhalation in humans?

The out flow of air is called Exhalation. It is also called as Expiration.

• The intercostal muscles and the diaphragm relax, allowing the thoracic cavity to return to its original, smaller size and increasing the pressure in the thoracic cavity.
• Abdominal muscles contract, pushing the abdominal organs against the diaphragm, further increasing the pressure within the thoracic cavity.
• The action in step 2 causes the elastic lungs to contract and compress the air in the alveoli.
• With this compression, alveolar pressure becomes greater than atmospheric pressure, causing air to be expelled (exhaled) from the lungs.

Q. What is Feedback system?

Feedback system is the system in which the controlling mechanism is itself controlled by the product of the reaction it is controlling.

Example: Incubator, Toaster, Iron.

• Positive Feedback
• Negative Feedback

Q. Write the role of chromaffin tisues?

• Chromaffin tissue is a group of neuroendocrine cells in the adrenal medulla that synthesizes steroid hormones.
• These hormones are adrenaline (epinephrine) and noradrenaline (norepinephrine)
• These hormones prepare some vertebrates for stressful emergency situations (fight and flight)

Q. Define external Respiration?

The process of acquiring oxygen and eliminating carbon dioxide is called external respiration. The exchange of oxygen and carbon dioxide occurs across respiratory surfaces.

Q. Write the process of Inhalation in humans?

The intake of air is called as Inhalation. It is also called as inspiration.

• Several sets of muscles, the main ones being the diaphragm and intercostal muscles, contract.
• The intercostal muscles stretch from rib to rib, and when they contract, they pull the ribs closer together, enlarging the thoracic cavity.
• The thoracic cavity further enlarges when the diaphragm contracts and flattens.
• The increased size of the thoracic cavity causes pressure in the cavity to drop below the atmospheric pressure.
• Air rushes into the lungs, and the lungs inflate.

Q. What is Hemocyanin?

• Hemocyanin is the most commonly occurring respiratory pigment in molluscs and certain crustaceans.
• Hemocyanin contains metallic copper, has a bluish color when oxygenated, and always occurs dissolved in hemolymph.

Q. What is serum?

Serum is plasma from which fibrinogens have been removed.