Objectives (5 - 7 minutes)

1. Understand the concept of excretion and its importance for living beings: The teacher must ensure that students have a clear understanding of what excretion is and why it is crucial for the survival of living beings. This can be done through an initial discussion, where the teacher can ask students to share what they know about the topic and then provide a more in-depth explanation.

2. Recognize and differentiate the types of excretion: Once students have a proper understanding of the concept of excretion, the teacher should introduce the different types of excretion. This can be done through presentations, where the teacher discusses each type of excretion and provides clear examples.

3. Apply the acquired knowledge to identify the type of excretion in different animals: Once students have a clear understanding of the different types of excretion, the teacher should provide examples of animals and ask students to identify the type of excretion these animals have. This can be done through classroom activities, where students work in groups to solve problems.

Secondary Objectives:

• Develop critical thinking and problem-solving skills: Through the proposed activities, students will be encouraged to apply the acquired knowledge to solve problems. This will help develop their critical thinking and problem-solving skills.

• Promote collaboration and teamwork: By working in groups, students will have the opportunity to collaborate and develop their teamwork skills. This is important, as collaboration and teamwork are essential skills that students will need throughout their lives.

Introduction (10 - 12 minutes)

1. Review of concepts: The teacher should start the lesson by briefly reviewing the concepts of cells, tissues, and organs, as well as their functions. This is essential for students to understand the complexity of the excretory system in animals. Additionally, the teacher can review the processes of respiration and digestion, as they are directly related to excretion.

2. Problem situation: The teacher can propose two hypothetical situations to grab students' attention and spark interest in the topic. The first one could be: 'Imagine you are a fish living in an aquatic environment. How would you get rid of the excess water and minerals you ingest?' The second one: 'Now, imagine you are a bird living in a dry environment. How would you get rid of the excess minerals you ingest without losing an excessive amount of water?'

3. Contextualization: The teacher should explain that excretion is an essential process for maintaining homeostasis in animals, that is, for the body to function in a balanced way. Furthermore, examples of diseases that affect the excretory system, such as renal insufficiency, can be mentioned to show the importance of the subject for human health.

4. Capturing students' attention: To make the Introduction more engaging, the teacher can share curiosities about excretion. For example, they can mention that reptiles and birds excrete uric acid, a solid substance that does not require as much water to be eliminated as urea, which is the main excretory product of mammals. Another interesting curiosity is that some animal species, like the platypus, are capable of storing urine in their cloacal pouches and releasing it only when they are in water, saving water in dry environments.

Development (20 - 25 minutes)

1. Practical Activity: Excretion Simulation (10 - 12 minutes)

   • Materials needed: Transparent plastic bottles, water, food coloring, salt, sand, sponge, and paper towel.

   • Preparation: Before the lesson, the teacher should fill half of the bottles with water (representing blood), adding food coloring to make it red. Then, different substances should be added to each bottle: salt (representing minerals), sand (representing toxic substances), and a mixture of salt and sand. Finally, a sponge should be soaked with water and placed in an empty bottle (representing the nephron).

   • Activity steps:

     1. The teacher should divide the class into groups and give each group a bottle.
     2. Students should discuss in their groups which substances represented in the bottle are excreted by the body and which are reabsorbed.
     3. Next, students should try to simulate the filtration and reabsorption process of the nephron. They should pour the water from the bottle (blood) into the sponge (nephron) and observe what happens. Then, they should pour the water from the sponge back into the bottle, but this time, holding the sponge to represent the reabsorption of useful substances.
     4. Finally, students should add the substance represented in the bottle that was not reabsorbed (salt, sand, or the mixture) and discuss what this may represent in terms of health problems.

2. Group Discussion Activity: Types of Excretion (10 - 12 minutes)

   • Activity steps:
     1. The teacher should divide the class into groups and give each group a list of animals and their respective types of excretion.
     2. Students should discuss in their groups why each animal has the listed type of excretion. They should consider factors such as the animal's habitat, diet, and physiology.
     3. Then, each group should present their conclusions to the class, promoting a classroom discussion.

These practical and group discussion activities will allow students to apply the acquired knowledge in an interactive and engaging way. Additionally, they will promote the development of critical thinking, problem-solving, and teamwork skills.

Return (8 - 10 minutes)

1. Group Discussion (4 - 5 minutes)

   • Steps:
     1. The teacher should gather all groups and start a group discussion. Each group will have up to 2 minutes to share their conclusions or solutions from the activity.
     2. While the groups are presenting, the teacher should ask questions to stimulate critical thinking and deepen students' understanding. For example: 'Why do you think this animal evolved to excrete in this way?' 'How does this animal's excretion contribute to its survival in its habitat?'
     3. The teacher should ensure that all groups have the opportunity to contribute to the discussion and that all questions are answered.

2. Connection to Theory (2 - 3 minutes)

   • Steps:
     1. After the presentations, the teacher should quickly review the key concepts covered in the lesson, linking them to the practical activities carried out.
     2. The teacher should clarify any misunderstandings and reinforce key points, ensuring that students have a clear understanding of the different types of excretion and how they apply to different animals.

3. Final Reflection (2 - 3 minutes)

   • Steps:
     1. To conclude the lesson, the teacher should propose that students reflect for a minute on answers to questions such as: 'What was the most important concept learned today?' and 'What questions have not been answered yet?'
     2. Students should share their reflections with the class. The teacher should encourage an open and respectful discussion, reminding students that all questions and ideas are valid and important.

This Return moment is essential to consolidate students' learning, allowing them to see the connection between theory and practice, and giving them the opportunity to reflect on what they have learned. Additionally, by asking questions and listening to students' reflections, the teacher can identify any gaps in understanding that need to be addressed in future lessons.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes): The teacher should recap the main points covered during the lesson, reinforcing the concept of excretion and the different types of excretion found in animals. They should emphasize how each type of excretion adapts to the environment and the specific needs of each species. The teacher can do this through a verbal or visual summary, such as a diagram or scheme.

2. Connection between Theory and Practice (1 - 2 minutes): Next, the teacher should emphasize how the practical activities carried out in the lesson helped illustrate and deepen students' understanding of the theoretical concepts. They should highlight the insights gained from the simulation of the excretion process and the discussion about the different types of excretion in real animals.

3. Additional Materials (1 - 2 minutes): The teacher should suggest additional study materials for students who wish to deepen their knowledge on the topic. This may include books, articles, videos, websites, and educational apps. For example, the teacher may recommend reading specific chapters of a biology book, watching documentaries about animal life, or exploring interactive online simulations of the excretory system.

4. Applications in Daily Life (1 minute): Finally, the teacher should highlight the importance of studying excretion for everyday life. They can mention how the human excretory system works to maintain the body's balance and the importance of good kidney health. Additionally, they can mention how understanding excretion in animals can be useful in areas such as veterinary medicine, wildlife conservation, and biotechnology.

At the end of the Conclusion, students should have a clear and comprehensive view of the topic of excretion in animals, understanding its significance, the different types, and how they apply to different animals. Furthermore, they should be encouraged to continue exploring the topic on their own, deepening their understanding and connecting theory to practice and real-world applications.