Gas Exchange in Plants (intercambio gaseoso)

As you have learnt in today's lesson, plants not only exchange gases in the photosynthesis, but also in respiration. Answer the following questions: 

1. When do they respire or breathe? 

2. What's the name of the tiny holes through which they do the respiration? 

3. What gas do they take in and what gas do they release in respiration?

4. Besides the leaves what do they use to breathe?