Lesson 1
Purpose of the work:
– to study the respiratory process in plants
– be able to distinguish between the respiratory process and photosynthesis in plants
Run time: 10 minutes
Observation time: 30 minutes
Expected results
After studying the project, students will be able to:
– Gain teamwork skills
– analyze and summarize the information received
– independently build logical reasoning and draw conclusions
Teacher’s guide:
1.To assess the project, provide this material (PBL rubrics) to students in order to:
– the students previously understood by what criteria they need to prepare,
– students were able to independently evaluate their colleagues.
2.Before proceeding with the laboratory work, please read the safety rules by clicking on the link: safety rules
3.Divide the students so that there are 3 students in each group.
4.To download the worksheet, please follow the link: Worksheet
Precautions:
- Use droppers to take the reagents from the bottle.
- Wear lab aprons and hand gloves during the experiment.
- While performing the experiment handle chemicals with care.
- Refer to the lab manual before beginning with the experiment.
- Be careful while handling chemicals and other acidic solutions.
Theoretical part
Respiration is the process of decomposition of organic substances in living cells under the influence of oxygen. As a result of respiration, carbon dioxide and water are formed, and the energy necessary for life is released.
How is the breathing process going?
When breathing, plants, like other living things, absorb oxygen from the air. They also use the oxygen produced in their cells during photosynthesis. During respiration, organic matter breaks down into water and carbon dioxide.
Plant respiration is ongoing process.
The process of respiration is opposite to the process of photosynthesis. Respiration is a prerequisite for the existence of plants, as it provides the plant organism with the energy necessary for life.
Sources:
- Дыхание у растений — урок. Биология, 6 класс. (yaklass.ru)
- <a href=”https://ru.freepik.com/free-vector/diagram-showing-process-of-cellular-respiration_13753886.htm#query=plant%20respiration&position=8&from_view=search&track=ais#position=8&query=plant%20respiration“>Изображение от brgfx</a> на Freepik
Practical part
In this work, we will experimentally prove that the process of respiration occurs in seeds, during which they absorb oxygen and release carbon dioxide. 2-3 days before laboratory work, it is necessary to germinate the bean seeds in advance. In germinating seeds, the respiration process is intense.
Step 1: Place the seeds in a clean glass flask.
Step 2. Pour clean water into another glass container.
Step 3: Place sodium hydroxide in the test tube and tie it with string. Warning! Sodium hydroxide is a strong alkali, so be careful when working with it and be sure to wear gloves!
Step 4. Make a hole in the plug equal to the diameter of the tube.
Step 5: Place the test tube in the flask and cap it with a plug.
Step 6. Build a U-shaped device from the tubes, as shown in the figure.
Step 7. Pass one end of the device through the plug and place the other end in a glass of water.
Step 8. Stick plasticine around the hole to prevent air from passing through.
Step 9: Mark the water level in the tube with a marker. Leave the finished structure for 30 minutes.
To summarize your work, write answers to the following questions:
What did you notice after the time passed? What changes have occurred?
What causes the water level in the tube to change?
How is this experience related to the process of plant respiration?
Conclusion
In this practical work, students studied the mechanism of the respiratory process in plants.
Evaluation
