Question

The gas-exchange portion of the human respiratory system is the-
A. Larynx
B. Trachea
C. Bronchi
D. Alveoli

Answer 1

Hint: The Lungs Are the Essential Organs of the Respiratory System. For gas exchange between the air we breathe and our bodies the lungs are responsible. Inside the thoracic cage, they are protected. Then the right, the left lung has two lobes and is slightly smaller in volume.

Complete answer:
-Larynx: In the upper respiratory tract the major passages and structures include the nose or nostrils, nasal cavity, mouth, throat (pharynx), and voice box (larynx). This is the incorrect option.
-Trachea: The human respiratory system is adapted to allow air to pass in and out of the body, and for efficient gas exchange to happen. Bronchioles are the bronchi that split into smaller branches and then into smaller tubes. This is the incorrect option.
-Bronchi: The bronchi delivers oxygen-rich air to the lungs, where gas exchange occurs in tiny air sacs called alveoli. Through the respiratory membrane which is the barrier and where oxygen and carbon dioxide are exchanged. This is the correct option.
-Alveoli: At the end of the bronchioles the tiny air sacs are known as alveoli. Where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out is known as alveoli.

Hence, option C: Bronchi is the correct answer.

Note: Gas exchange during respiration occurs primarily through diffusion. A Process in which transport is driven by a concentration gradient is known as diffusion.