Objectives (5 - 7 minutes)

1. Understand the importance of the excretory system and the excretion of waste in animals, understanding how they help maintain the organism's balance.

2. Identify and describe the different types of excretion found in animals, including ammonia, urea, and uric acid.

3. Relate the types of excretion to the different environments in which animals live, explaining how each type contributes to the survival and adaptation of these organisms.

   Secondary Objectives:

   • Stimulate active student participation through questions and discussions throughout the class to ensure understanding of the concepts.

   • Promote critical thinking by questioning how different forms of excretion can impact the environment and human health.

Introduction (10 - 15 minutes)

1. Review of Previous Content: The teacher should start the class by reviewing the basic biology concepts that are prerequisites for understanding the excretory system, such as cells, tissues, organs, systems, and homeostasis. This review can be done through direct questions to students or a brief summary presented by the teacher. (3 - 5 minutes)

2. Problem Situations:

   • The teacher can propose a situation in which an animal is in an environment with limited access to water. How should this animal excrete its waste to maximize its survival? (2 - 3 minutes)
   • Next, the teacher can present another situation in which an animal lives in an environment with excess water. How would the waste excretion of this animal be different from the previous situation? (2 - 3 minutes)

3. Contextualization: The teacher should explain the importance of studying the excretory system, showing how this system is crucial for maintaining homeostasis in animals and how understanding its different forms of excretion can help better understand the adaptation of animals to different environments. The teacher can also discuss the relevance of the subject to human health, showing how diseases that affect the excretory system, such as renal failure, can have a significant impact on people's lives. (3 - 4 minutes)

4. Generating Interest:

   • The teacher can arouse students' curiosity by sharing some curiosities related to the excretory system, such as the fact that kangaroos excrete urine so concentrated that it can be used for hydration in emergency situations. (1 - 2 minutes)
   • Next, the teacher can present a short video or an image of an exotic animal that has a particularly interesting type of excretion, such as the kiwi bird, which excretes uric acid in the form of a white paste instead of liquid urine. (1 - 2 minutes)

Development (20 - 25 minutes)

1. Theory: Introduction to the Excretory System (5 - 7 minutes)

   1. The teacher should start by explaining that excretion is the process by which organisms get rid of the waste from their metabolism.
   2. Next, the excretory system should be presented, which is the set of organs responsible for this function in animals, including the kidneys, ureters, bladder, and urethra in humans.
   3. The teacher should explain that the excretory system not only excretes waste but also plays a vital role in regulating the balance of water, salts, and other chemicals in the body.
   4. The teacher can use diagrams and models to illustrate the structure and function of the organs of the excretory system.

2. Theory: The Three Types of Excretion (5 - 7 minutes)

   1. The teacher should introduce the three main types of excretion in animals: ammonia, urea, and uric acid.
   2. For each type, the teacher should explain how it is produced, how it is transported out of the body, and the advantages and disadvantages of its use.
   3. The teacher should emphasize that the choice of excretion type is determined by the environment in which the animal lives and the amount of energy available for excretion.
   4. The teacher can use examples of animals that use each type of excretion to help illustrate these points.

3. Theory: Adaptation of the Excretory System to the Environment (5 - 7 minutes)

   1. The teacher should explain how the different types of excretion are related to the different environments in which animals live.
   2. It should be discussed how animals living in aquatic environments, where water is abundant, tend to excrete ammonia, which is highly toxic and soluble in water.
   3. On the other hand, animals living in terrestrial environments, where water is scarce, tend to excrete urea or uric acid, which are less toxic and less soluble in water but require more energy to be produced.
   4. The teacher can use examples of animals living in different environments to illustrate these points.

4. Practice: Application Activities (5 - 7 minutes)

   1. The teacher should propose some activities for students to apply what they have learned. For example, students can be divided into groups, and each group can receive a problem situation related to excretion in a specific environment. Students should discuss and present solutions based on what they have learned.
   2. Alternatively, students can be invited to research and present real examples of animals living in different environments and using different types of excretion.

Feedback (10 - 12 minutes)

1. Group Discussion (5 - 6 minutes):

   • The teacher should promote a group discussion so that students can share their solutions or conclusions from the activities carried out. Each group will have up to 2 minutes to present.
   • During the presentations, the teacher should ensure that all important concepts about the excretory system and the different types of excretion are being correctly addressed.
   • The teacher should encourage other students to ask questions and make comments, thus promoting a collaborative learning environment.

2. Connection with Theory (2 - 3 minutes):

   • After the presentations, the teacher should reinforce the concepts discussed during the class and make the connection with the solutions presented by the groups.
   • The teacher can highlight how the different types of excretion are related to the adaptation of animals to different environments, reinforcing the importance of the excretory system for the survival and homeostasis of animals.

3. Individual Reflection (3 - 4 minutes):

   • To conclude the class, the teacher should propose a moment of individual reflection. Students should think about what they have learned and mentally answer the following questions:
     1. What was the most important concept I learned today?
     2. What questions do I still have about the excretory system and the different types of excretion?
   • The teacher can encourage students to write down their answers, which can be used as a basis for the next class or for review activities at home.

4. Feedback and Closure (1 minute):

   • The teacher should end the class by thanking the students for their participation and providing general feedback on the class.
   • The teacher should reinforce that understanding the excretory system and the different types of excretion is fundamental for the study of biology and for understanding the functioning of the human body.
   • The teacher should also remind students to study the class content and to ask questions in the next class or at any other time they need.

Conclusion (5 - 7 minutes)

1. Recapitulation (2 - 3 minutes):

   • The teacher should start the Conclusion by recalling the main points discussed during the class, emphasizing the importance of the excretory system and the different types of excretion for maintaining homeostasis in animals.
   • The teacher can briefly review the three types of excretion (ammonia, urea, and uric acid), explaining again how each one is produced and what are its advantages and disadvantages.
   • The teacher should also reinforce the relationship between the types of excretion and the different environments in which animals live, highlighting how evolution favored the adaptation of animals to these environments through the selection of different types of excretion.

2. Connection of Theory, Practice, and Applications (1 - 2 minutes):

   • The teacher should explain how the class connected theory, practice, and applications.
   • It should be emphasized that the theory was presented clearly and didactically, using examples and activities to facilitate students' understanding.
   • The teacher should also highlight how the application activities allowed students to apply what they learned in a practical way, promoting a more meaningful learning.

3. Supplementary Materials (1 minute):

   • The teacher should suggest supplementary materials for students who wish to deepen their knowledge about the excretory system and the different types of excretion.
   • These materials may include biology books, reference websites, educational videos, and interactive games on the subject.
   • The teacher can provide a list of these materials at the end of the lesson plan or send them by email to the students.

4. Importance of the Subject (1 - 2 minutes):

   • To conclude, the teacher should summarize the importance of the subject addressed for students' daily lives.
   • It should be highlighted how knowledge about the excretory system and the different types of excretion can help better understand the functioning of the human body and the importance of health and well-being.
   • The teacher can also mention how understanding these concepts can be useful in various careers, such as medicine, biology, ecology, veterinary medicine, among others.
   • The teacher should end the class by reinforcing the relevance of the subject and encouraging students to continue studying and exploring the topic.