Introduction
This unit bundles Student Expectations that address the levels of organization within the human body. The human body consists of interconnected organ systems and each performs specific, essential functions for life. Changes in motion that occur within organisms are caused by forces. Organisms have specific responses to stimuli in order to maintain homeostasis. During digestion, food is broken down into its chemical components in order to provide energy and nutrients to the body.
Prior to this Unit
Grade 4
4.6D – Design a descriptive investigation to explore the effect of force on an object such as a push or a pull, gravity, friction, or magnetism.
Grade 5
5.6D – Design a simple experimental investigation that tests the effect of force on an object.
Grade 6
6.5C – Identify the formation of a new substance by using the evidence of a possible chemical change such as production of a gas, change in temperature, production of a precipitate, or color change.
6.8B – Identify and describe the changes in position, direction, and speed of an object when acted upon by unbalanced forces.
Grade 7
7.12C – Recognize levels of organization in plants and animals, including cells, tissues, organs, organ systems, and organisms.
During this Unit
Students study human body systems for the first time, including the circulatory, respiratory, skeletal, muscular, digestive, excretory, reproductive, integumentary, nervous, and endocrine systems. They identify the main functions of the systems of the human organism. They apply their knowledge of the levels of organization in animals, including cells, tissues, organs, organ systems, and organisms. Students understand that a combination of parts can perform functions that the single parts cannot perform alone. They apply their knowledge from the previous unit to compare the functions of a cell to the functions of organisms. Students use scientific practices and tools to investigate how organisms respond to external stimuli found in the environment, such as fight or flight. Additionally, students describe and relate responses in organisms that may result from internal stimuli, such as fever or vomiting in animals, that allow them to maintain balance. Furthermore, students learn that forces from muscle actions cause motion, such as circulation of blood, movement of bones, the movement of food through the digestive system, and inhalation / exhalation. Finally, they distinguish between the physical and chemical changes in matter within the digestive system. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
After this Unit
In Grade 8, students will expand their understanding of force and motion to include the study of Newton’s laws of motion and their applications. Students will study animal systems and homeostasis in greater depth in High School Biology.