CBSE Questions for Class 7 Biology Respiration In Organisms Quiz 3 - MCQExams.com

• The act of breathing out air from the lungs is called exhalation. By this process, the waste product of respiration i.e. CO$$_{2}$$ is expelled out of the lungs.
• Inhalation is the process when we take in air containing oxygen.
• Assimilation is the movement of digested food molecules into the cells of the body where they are used. 
• The process of absorption means that a substance captures and transforms energy.

• The act of taking in air into the body through nostrils is called inhalation. By this process, fresh air enters the lungs that contain a large amount of oxygen.
• Exhalation is when we give out air rich in carbon dioxide. 
• Ingestion is the process of taking in food through the mouth.
  
• Absorption is defined as the process when one thing becomes part of another thing.
  

• The plant's roots are embedded into the soil. 
• The soil has air spaces that allow the tip of the roots to take up oxygen and then this is used by the cells of the root for respiration.

Roots have hairlike projections called root hairs protruding from their surface. These root hairs help the plant absorb more air, nutrients and water because they increase the available surface area.

• Soil porosity is important for many reasons. A primary reason is that soil pores contain the groundwater that many of us drink.
• Another important aspect of soil porosity is that the oxygen found within these pore spaces. 
• All plants need oxygen for respiration, so a well-aerated soil is important for growing crops. Hence, the soil pores help in storage of air and storage of water.

The process by which cells obtain chemical energy by the consumption of oxygen and the release of carbon dioxide is known as respiration. To carry on respiration, plant cells need oxygen and a means of disposing of carbon dioxide just as animal cells do. In plants, each part such as root, stem performs respiration because plants do not possess any specialized organs like animals for the exchange of gases.

The process of respiration is expressed as:

Glucose + Oxygen → Carbon Dioxide + Water (+ Energy)

$$\textbf{Correct Option B}$$

$$\textbf{Solution}$$

$$\bullet$$ $$\textbf{Option A}$$ Nodules  are found in the roots of the plant and they are caused due to the infection of the roots by some of the bacteria present in the soil.

$$\bullet$$ $$\textbf{Option B}$$ Stomata  are small pores present on the surface of the leaves which helps in the exchange of gases during the process of photosynthesis. They are also required during the process of transpiration, through which the water vapor escape into the atmosphere.

$$\bullet$$ $$\textbf{Option C}$$ Radical are the embryonic root of the plants which grows downwards towards the ground to provide water to the growing plant.

$$\bullet$$ $$\textbf{Option D}$$  This is not the correct option.

So, the correct option is B.