BIO_PSE_U1-pages-1.pdf

UNIT 1 Living Systems Lesson 1: Life in the Earth System.... 4 Lesson 2: Organisms: Cells to Body Systems..................16 Lesson 3: Mechanisms of Homeostasis...................32 Lesson 4: Bioengineering..........48 Thing Explainer: Bags of...

UNIT 1 Living Systems Lesson 1: Life in the Earth System.... 4 Lesson 2: Organisms: Cells to Body Systems..................16 Lesson 3: Mechanisms of Homeostasis...................32 Lesson 4: Bioengineering..........48 Thing Explainer: Bags of Stuff Inside You...................62 Unit Connections..................66 Unit Review.......................67 Unit Performance Task.............69 Image Credits: ©Living Art Enterprises/Science Source The human heart is one component in a larger living system. 2 Unit 1 Living Systems  FIGURE 1: Each bat is a living system. Living and nonliving systems are all around you. Nonliving systems help you complete many tasks, such as cars and buses to travel to school or cell phones to make a call. Organisms, such as bats, are examples of living systems. Cells in bats work together to perform all of the functions necessary for life. For example, structures in bats’ wings help them maintain water balance in their bodies. Bats and other living and nonliving things are part of larger systems on Earth. Predict How do you think living systems such as bats carry out life functions and respond to changes in the environment? DRIVING QUESTIONS As you move through the unit, gather evidence to help you answer the following questions. In your Evidence Notebook, record what you already know about these topics and any questions you have about them. 1. What are the levels of organization within the Earth system? 2. How do systems in living things interact to maintain the organism? 3. How does the structure of cells relate to different functions and specialization? 4. How have advances in technology influenced human health and society? Image Credits: ©Visionary Earth/Shutterstock UNIT PROJECT Go online to download Investigating Plant Systems the Unit Project Worksheet to help plan your project. A seedling is a living system made up of different components. Grow seedlings and investigate how they interact with other systems to survive and grow in changing conditions. Can you explain the levels of organization within your seedlings and the environment, from cells to ecosystem? Unit 1 Living Systems 3  1.1 Life in the Earth System CAN YOU EXPLAIN IT? FIGURE 1: Although the robot in this image is conceptual, robots can be programmed to Certain conditions make life carry out very complex tasks, such as playing a game of chess. sustainable on Earth. Image Credits: (t) ©StockTrek/Photodisc/Getty Images; (b) ©Blutgruppe/Corbis Gather Evidence Humans have used technology since early times. Today we may be quick to name As you explore the lesson, cellular phones and computers as examples. However, technology includes even gather evidence to make a claim simple things, such as a fork or a pen, basically any tool, process, or system that is about what defines a living system. designed to solve a problem. Robotic technology has advanced to human-like form. Robots can perform work, including tasks that are difficult or dangerous, but they also can provide companionship and health care. Consider the players in this chess game. The robot and the human have parts that perform similar functions and have a control center to guide their actions. They are both systems that can perform many of the same tasks. Predict Imagine a company that sells robots like the one shown in Figure 1. The company makes the claim: “This living machine is the perfect companion.” Make a case to either support or refute this claim. How similar are living and nonliving systems? 4 Unit 1 Living Systems EXPLORATION 1 Systems and System Models Throughout history, humans have strived to understand the world around us. To help make sense of the observed phenomena, we organize information and identify patterns. One approach to understanding natural phenomena is called systems thinking. This way of thinking examines links and interactions between components, or parts of a system, to understand how the overall system works. Properties of Systems A system is a set of interacting components considered to be a distinct entity for the purpose of study or understanding. The robot and human at the beginning of the lesson are both systems. camera FIGURE 2: To Collaborate Discuss send a text this question with a message, a cellular partner: What systems could you phone requires define in the world around you? components, such as a signal receiver and transmitter, a microphone battery, a circuit board, and a screen screen. circuit battery board connector and antenna Boundaries and Components Analyze What is the Boundaries define the space of the system to separate that system from the rest of the boundary of the human universe. A cellular phone is a system of electronics contained in a protective covering. body? What is the boundary of a The components are all the parts of the system that interact to help the system carry out specific functions. For example, a cellular phone needs the parts described in robot? Compare the inputs and Figure 2 to function properly. Together, the components send and receive radio outputs of humans and robots in signals and transform them into useful communication, such as text messages. terms of matter and energy. Inputs and Outputs The inputs and outputs of different types of systems include energy, matter, and information. Outputs are generated when the inputs are processed in some way. In the case of a cellular phone, a radio signal (an input) is converted to vibrations (an output) that you detect as sound. Lesson 1 Life in the Earth System 5  Open and Closed Systems Systems can be categorized according to the flow of inputs and outputs. In an open system, the inputs and outputs flow into and out of the system. In a closed system, the flow of one or more inputs and outputs is limited in some way. An isolated system is a system in which all of the inputs and outputs are contained within the system. Analyze Is the human body an open, closed, or isolated system? What about a robot? Explain your answer. Controls The components of a system include the controls that help keep the system working properly by monitoring and managing the inputs and outputs. Controls can be automatic, manually set, or a combination of both. An important system control is feedback. Feedback is information from one step of a cycle that acts to change the behavior of a previous step of a cycle. So, feedback is output that becomes input. A feedback loop is formed when an output returns to become an input in the same system that generated the output. Systems and System Models Model Draw a simple FIGURE 3: A thermostat can be used to control the heating and cooling systems diagram showing how a in a home. thermostat would respond when the temperature in a room rises above the set point. Some air conditioners and heaters have a control system called a thermostat, such as the one shown in Figure 3. A thermometer inside the thermostat continually measures the temperature in the room. If the air temperature in the room rises above a preset temperature, the thermostat signals the air conditioner to turn on. If the air temperature in the room falls below the preset temperature, the thermostat Image Credits: ©iStock/Getty Images Plus/koinseb signals the air conditioner to turn off. 6 Unit 1 Living Systems  System Organization Systems can range in size and in complexity. For example, a thermostat is a small, relatively simple system. The chess-playing robot is a larger, very complex system. The Earth system is larger still and is itself a part of the solar system, the Milky Way galaxy, and the universe. More complex systems generally have more levels of organization than simpler systems. For example, organisms, or living things, are systems made up of smaller systems, such as organs, tissues, and cells. Two organisms that interact also can make up a system, such as a bird that pollinates a plant. On a larger scale, you are a system that is part of an ecosystem, or community of organisms, and their physical environment. You also are part of the larger Earth system. FIGURE 4: Both the hummingbird and the thistle plant are systems that interact with one another. They are part of an ecosystem, such as a city park. Image Credits: (tl) ©Don Mammoser/Shutterstock; (tr) ©Ben Blankenburg/Fotolia; (b) ©Photographer’s Choice RF/Georgette Douwma/Getty Images As mentioned earlier, an output of a system can feed back into the system, changing Gather Evidence how the system may respond. Similarly, an output of one system can act as an input How do your interactions to a completely different, perhaps even unrelated, system. Think about walking into with nonliving systems affect your an air-conditioned building on a hot day. The cool air becomes an input to your body environment? system as receptors in your skin detect the change in air temperature. You may even begin to shiver slightly: the body’s response when it senses cold temperatures. FIGURE 5: A scuba diver and the scuba gear she wears are two systems interacting. Explain The scuba diver is a living system. The scuba gear, or self-contained underwater breathing apparatus, is a system of air exchange. How are these two systems interacting? Lesson 1 Life in the Earth System 7