The question asks to identify the primary site for gas exchange in the human respiratory system. To answer this, we need to recall the structure and function of different parts of the respiratory tract.
C) Alveoli are the tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide between the air and the blood takes place. Their structure, characterized by a large surface area, thin walls, and rich capillary network, is perfectly adapted for this function.
The question asks to identify the reasons for multi-drug resistance (MDR) in microbial pathogens in India. We need to evaluate each given statement to determine its contribution to MDR.
B) 2 and 3 only. Statements 2 and 3 accurately describe practices that lead to the development and spread of multi-drug resistance in microbial pathogens.
The question asks to identify the structure responsible for preventing food from entering the larynx (windpipe) during the act of swallowing. This involves understanding the anatomy and physiology of the upper respiratory and digestive tracts.
Correct Option: B) Epiglottis
The question asks for the average tidal volume in a healthy human. Tidal volume is the amount of air that moves in or out of the lungs with each normal breath. We need to recall the typical physiological values for respiratory volumes.
Therefore, 500 mL is the correct average tidal volume.
Correct Option: C) 500 mL is the average volume of air inspired or expired during a normal, quiet breath in a healthy human.
The question asks about the primary function of B cells and T cells in the human body. This relates to the immune system's components and their specific roles in defending the body.
Correct Option: D) They protect the body from the diseases caused by pathogens.
This statement accurately describes the primary function of both B cells and T cells, which are central to the adaptive immune response against disease-causing microorganisms (pathogens).
The question asks to identify the muscle whose contraction directly leads to an increase in thoracic volume during the process of inspiration (breathing in). This requires knowledge of the primary muscles involved in respiration and their actions.
Correct Option: A) Diaphragm — The contraction of the diaphragm causes it to flatten and move downwards, thereby increasing the vertical dimension of the thoracic cavity. This increase in volume is crucial for decreasing intrapulmonary pressure and drawing air into the lungs during inspiration.