CBSE Questions for Class 7 Biology Respiration In Organisms Quiz 2 - MCQExams.com

• The diaphragm is a thin muscular membrane that sits at the base of the chest cavity and separates the abdomen from the chest. 
• When we inhale, it contracts, and the air moves into the lungs. When we exhale, it relaxes, pushing air out of the lungs. 

• Respiration includes two processes: inhalation and exhalation.
• Inhalation (also known as inspiration) occurs when air or other gases enter the lungs.
• Exhalation is the process by which the body expels carbon dioxide. 

• Anaerobic respiration is a form of cellular respiration that occurs when oxygen is absent.
  
• The substrate glucose is broken down into alcohol and carbon dioxide in yeast and plants. In human muscles when oxygen supply is less substrate glucose is broken down to lactic acid anaerobically.
• So, the correct answer is option C.

$$\textbf{Correct Option D}$$

$$\textbf{Solution}$$

$$\bullet$$Strenuous exercise are the activities which needs a lot of effort, energy and strength.Some of the examples of these activities are calisthenics, jogging, swimming etc.

• During inhalation, the ribs move upward and outward which increases the volume of the chest cavity.
• During exhalation, the ribs move downward and inward to decrease the volume of the chest cavity.

• When you breathe in, or inhale, your diaphragm moves downward and the ribs move upward and outward. This increases the space in your chest cavity, into which your lungs expand.
• So, the correct answer is 'True'.

$$\textbf{Correct option:B}$$ 

$$\textbf{Solution:}$$

$$\bullet$$ During exhalation ,the air is composed of foul air which contains carbon dioxide,water vapor as the mouth and lung both have moisture content and this is released in the form of water vapor,the gas form of water.

$$\bullet$$ Therefore ,we lose water molecules as we breathe every time which is not the same case for inspiration which is purely composed of oxygen and nitrogen.

$$\textbf{Hence, the correct option is (B)}$$