Life Sciences Grade 11 (Term 3, Gaseous Exchange)



Gaseous Exchange

Gaseous exchange is an involuntary process that occurs in plants, insects, animals and humans. Gaseous exchange takes place in the lungs and in the cells of the body. The structure of the lung is adapted to fulfil the function of gaseous exchange.  It is also known as Internal Respiration. In mammals, such as animals and humans, gaseous exchange takes place on the inside of the body. During this process, gasses are exchanged between the lungs, blood and body cells. Watch the attached video for more information.



At the end of this WebQuest you will have acquired the following knowledge and be able to answer the following questions:

  • Why do we have to breathe?
  • Are our lungs like big balloons in our chest, or what do they look like?
  • How does the oxygen in the air that we breathe in pass from our lungs into our blood?
  • How does blood move around our bodies and get to each cell to deliver oxygen?
  • We know that carbon dioxide is produced as a waste product in cellular respiration, so how is it removed from our bodies?
  • How are the circulatory and respiratory systems linked?
  •  What Gas exchange is. 
  • How gas exchange occurs in different animals, plants and insects. 
  • How that the responsible organs used for gas exchange differ from one animal to another. 
  • That all animals, insects and plants need to meet the same requirements for efficient gas exchange to take place. 
  • That there are differences between animals in aquatic and animals in terrestrial environments. 

Step 1

1. Click on the YouTube Link below and watch the video clip.

Gaseous exchange in different animals 

2. After watching the video, write down your name and surname on a word document, followed by the answers to the following questions: 

  • How does animals exchange gases? Is it different to that of humans? 
  • How does insects exchange gases?
  • What does all the animals in the video have in common, that allows them to exchange gases? 

Step 2

1. Click on the YouTube Link below and watch the video. 

2. On the word document that you have created, continue by answering the questions that will follow below. 

Exchange of gases in aquatic and terrestrial animals. 

  • How do fish breathe under water? What organs do they use? 
  • How does aquatic animals exchange gasses differently than terrestrial animals? What challenges are there?

Step 3

1. Click on the YouTube Link below, watch the video and answer the questions that follows on your word document, below the previous answers. 


  •  At which part of the plant does gas exchange occur? 
  • What are the pores called where gas exchange occurs? 
  • List one requirements for efficient gas exchange organs? 
  • After answering all these questions, save your word document and rename it using your initials and surname. 
  • Lastly submit by sending it to me using my email which i have provided in our previous lesson. 



The mark allocation for the questions above is as follows:

The Questions in:

Step 1 (3 questions) =2 marks each. 

Step 2 (2 questions) = 3 marks each.

Step 3 (3 questions) =1 mark each.


Total marks that can be scored: 15


Gas exchange is very important in order for life to continue on planet earth. Humans, animals, insects and plants all need to obtain oxygen and get rid of carbon dioxide in order to live. If this process should be interrupted or hindered, life would sadly cease to exist.

This WebQuest was designed to help you to learn about gaseous exchange and its importance. For further learning on the topic, use the links provided below.,dioxide%20to%20prevent%20its%20accumulation

Teacher Page

Created by Siphelele Nkebethwane, Life Sciences student teacher for Grade 11.