How Do Cows Grow? Presentation Animals Lesson 4.1 How Do Cows Grow? Presentation Lesson 4: Activity 1

Driving question: How do cows grow? Tell students to think about how other animals grow. Tell students that all of the things they discussed about mealworms can be applied to all animals. So, for example, animals like humans eat food that contributes to our mass. Cows eat grass or grain that contributes to its mass. Tell students that they will transition to a bigger, more interesting animal, a cow, to talk about food and body composition. Ask students what a different animal, a cow, needs to grow.   What does a cow need in order to grow? How does a cow use these things in order to grow?

What are the inputs and outputs of a cow’s body? Have students make a list of all the inputs and outputs of a cow’s body

Inputs and outputs of a cow’s body Explain any inputs or outputs the students missed. Ask students what they think happens to food inside a cow’s body, based on the inputs and outputs of a cow’s body. Tell students that mealworms and cows have the same inputs and outputs. Remind students that “atoms last forever” so the inputs to a cow’s body must go somewhere, and the outputs to a cow’s body must have come from somewhere. Can you determine what happens inside cow’s body based on these inputs and outputs?

Matter entering and leaving animals Materials in a cow Materials in grass (materials entering cow) minerals H2O Carbohydrates minerals Protein minerals Protein H2O Fat Fat Protein H2O CO2 minerals Zoom into a molecular scale to learn what these inputs and outputs are like at an atomic-molecular level. Identify the organic materials and types of molecules in the inputs and outputs. H2O Carbohydrates minerals Materials leaving cow by breathing, urination and perspiration Cow’s feces

Flow chart of tracing food inside the body (large organic molecules) Digestive system Digestion Circulatory system Small organic molecules All body tissues Biosynthesis Animal biomass (large organic molecules) This slide illustrates the movement of food inside the body. Tell students that today we are following the red arrows, which show how food entering the body results in animal growth. The important body systems involved are the Digestive system and the Circulatory system. The name of the processes involved are digestion and biosynthesis. Biosynthesis occurs in all body tissues and is the process responsible for growing (building up the entire body). Tell students that when we talk about “growing” we mean “adding mass” and not “getting older.” In this flow chart the atomic-molecular scale is represented by “large organic molecules” and “small organic molecules.” Tell students that they will think more about the atomic-molecular scale, especially understanding the difference between large and small organic molecules, and where in the cow digestion and biosynthesis occurs (digestive system, circulatory system, and all body tissues) in the next two activities.. For animal growth