DTSE 2007: Lesson 1.2

NESTED STRUCTURE 1

LESSON 1.2

TITLE: Cancerous cells vs. Normal Cells

INTRODUCTION: Students will be introduced to images of cancerous cells and cancerous body parts and will compare those to images of non-cancerous cells and healthy body parts. Working in pairs, the students will be provided with a worksheet to fill out to help them theorize about and analyze the differences between cancerous and non-cancerous cells. Students will be asked to research the differences between cancer cells and normal cells to complete their worksheet. They will then use their data to write a cohesive summary containing the information they gathered. The goal here is for students to understand that cancer cells are the result of abnormal cell division and that is the difference between cancer cells and healthy cells.

OBJECTIVE: Students will become aware that all tissues and body parts are made of cells, thus cells are the basic unit of life. Students will understand that cells can divide and create more cells and this is the only way in which new cells can arise. Students will learn that sometimes cell division can be abnormal resulting in more cells than needed (creating a cancerous tumor). Students will find and use reliable sources of information to solve the problem. They will use that information to form valid conclusions. By working together to find these differences and defining them they are realizing that science is a social endeavor.

STUDENT PRECONCEPTIONS: There seems to be a trend of misconceptions that students have when understanding what cancer looks like at the molecular level. Many students are under the impression that tumors have many veins and blood, etc. that are seem at the microscopic level but not necessarily more cells. Students often do not realize that tumors are made up of many cells and therefore are confused about the cellular basis of cancer.

STANDARDS: The purpose of this lesson is to help students towards understanding the information in the following standards:

NSES-National Science Education Standards (NRC) Content Standard C: As a result of their activities in grades 9-12, all students should develop understandings of the cell:

The cells multiply and differentiate to form the many specialized cells, tissues and organs that comprise the final organism.

Project 2061

1.	Complex interactions among the different kinds of molecules in the cell cause distinct cycles of activities, such as growth and division 2.	Investigations are conducted for different reasons, including to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.

MATERIALS: Option A:       Microscopes- 7-10 Prepared slides of cancer cells Color Images of cancer cells, healthy cells Color Images of cancerous organs, healthy organs Worksheet

Option B:      Computers- 2-3 students per PowerPoint presentation saved on CD	      Worksheet Projector

PREPERATION:

1.	Before the class period begins the teacher should make sure he/she has access to the proper materials for presenting the visuals in this lesson. For the duration of this lesson plan the materials described in Option B will be used (See Materials in the previous section). 2.	The teacher should set up stations around the room appropriate to accommodate 2 students/station. Each station should be equipped with a lab-top or personal computer and have access to Microsoft PowerPoint. 3.	Load the attached PowerPoint slides to each individual computer. Open the slides and have them up on the screen and ready for the students to look at as soon as they sit down. *Make sure all computers are starting at the same spot (each screen should look identical) so that instructing the students through the PowerPoint isn’t a problem.

TIME: This is intended to be a two (45 minute) period lesson over two days. The first day students will examine the images provided and fill out their worksheet. For homework they can research more information on cancer cells. During the second period they can compare notes and complete their summaries.

SPECIAL INSTRUCTIONS: Depending on teacher resources the materials used to present information can vary.

Option A:

This can be done if you can create different stations each with a microscope, prepared slides, and an image of a whole organ. The prepared slides consists of cancer tissue and regular tissue samples to be compared with the image of cancerous or healthy organ. Brunel Microscopes offer a set of prepared Mammalian Tumor slides and can be purchased on their website: www.brunelmicroscopes.co.uk/slides-tumour.html. Professionally photographed images can be purchased online from www.sciencesources.com. Images are also available on the web and can be color printed on a desktop computer.

Option B This option would be to equip groups of 2-3 students with a computer loaded with your PowerPoint slideshow of images on various cells and organs, with and without cancer. Or if computers are not available, the instructor can present the slideshow using a projector and the class can work together.

ACTIVITIES: The focus of this lesson is to enable students to bring together their current knowledge of cell theory with their understanding that cancer is a negative disease and let them examine and observe the difference between cancerous body parts and normal body parts on both the macro and micro levels.

Day 1

1.	Once the period begins the teacher should introduce the class to the concept that cancer is a disease within our very own cells. Discussion should address cell theory-specifically that cells come from cells as well as cells are the basic unit of life. Questions to ask may be: “ How do new cells arise?” “What are our organs made of?” ”What is the human body comprised of?” 2.	Group the students into pairs and send each pair to a station. Give each student a worksheet to record what he or she observes from the PowerPoint slides. 3.	Remind students to bring their observation worksheets back to class the next day. Also, have students research more information on cancer cells for homework.

Day 2

1.	Have students who worked in pairs the previous day discuss and compare their observation worksheets with another pair of students. Have them identify similarities as well as differences in their observations. 2.	Have the various groups contribute their data to a list written on the board by the teacher. The teacher can list some of the common similarities and big differences on the board for the whole class to see. 3.	Give students the rest of the period to write a summary about their observations. Allow them to use both their worksheets as well as the information written on the board to construct their summary. 4.	Collect both the summary and the worksheet for grading.

ASSESSMENT: The students will be assessed on their summary, which should contain information from their worksheet as well as an analysis of the information by them. The variables assessed here are: •	Content Cell theory- all individuals are made of cells and cells come from cells •	Science Process/inquiry Students will be able to discuss and theorize ideas in groups. Students will be able to find reliable and valid sources for their data. Students will be able to interpret and reach conclusions from valid data. •	Nature of Science Evidence based

SUPPLEMENTARY MATERIALS: 1. Student Worksheet 1 2. PowerPoint slides saved on CD 3. Prepared Slides 4. Color Images