Biology Standard III, Objective 1

Title: Structure and Function

Description: Students will use a heart and a flower to relate the structure of an organ to the function of the organ.

Materials Needed: Shoes of different types (sandal, athletic, dress, hiking boot), Worksheet (below), optional: real flower or heart or movie of heart beating

Time Needed: 50 minutes

Procedures: 1. Start by making sure students understand what is meant by “structure” and “function”. Use the shoes to ask how the structures of each shoe determine its function. Make sure students are clear on this before going on. 2. If a video is available, show the clip of the heart beating or if you have an example of a heart or a flower, show it to the students and ask if it is just an accident how they look. Hopefully, students will realize that there is a reason for the structure of an organ. 3. Work with the students to write a detailed description of what a part of the heart (ex: the coronary arteries) look like, using a real heart or a diagram. The description should include size, shape, surface texture and suppleness. Then have the students describe why these characteristics help the coronary arteries do their job. 4. Instruct students to fill in the data table for each organ part and decide how that helps their function. Suggest that they use their textbooks to help. 5. If available, provide each student group with a flower to dissect. They can carefully describe each part as they remove it from the flower. Student Sheet Name______

Title: Structure and Function

Introduction: The form or structure of the organs in living things is an amazing match to the job or function that needs to be done. In this activity you will look carefully at the parts of two important organs, a heart and a flower, to see how nature has evolved organs beautifully designed to do their jobs.

Procedures:

1. Use the drawings below, your textbooks and other models your teacher provides to clearly describe the parts of the heart and flower. Fill in the table for each part. 2. Fill in the second part of the data table to show how the form of that part helps it perform its job. An example has been done for the coronary arteries. 3. Continue on with the flower, using your book, the diagrams provided and perhaps even a real flower. 4. Return to this page to answer the analysis questions.

Analysis:

1. Why does the left ventricle have thicker, more muscular walls than the right ventricle?

2. Which valves, the tricuspid and mitral or the pulmonary and aortic, would need to stronger? Why?

How does their structure support your answer?

3. Why do you think coronary arteries are found on the outside of the heart and not the inside?

4. Why are flower petals brightly colored and attractive?

5. How is the structure of a self-pollinating flower different from a flower that cross- pollinates (relies on pollen from another flower for fertilization)?

Conclusion: The Heart aorta

Coronary arteries

Part Description of it’s Structure How that affects its function: Small branching tubes on the They can flex with the heart as it Coronary outside of the heart. They beats and are small enough to deliver arteries have thin walls with flexible blood to each cell of the heart sides. muscle.

Atrium

Ventricle

Tricuspid and Mitral valves

Aortic and pulmonary Valves

Aorta and Pulmonary Vein The flower

Part Description of it’s Structure How that affects its function:

Petals

Stamen

Filament

Stigma

Ovary

Ovule

Sepal

Nectary