Purpose of Lesson

Cell Investigation

Purpose of Lesson

Students will learn the different organelles present in plant and animal cells to distinguish between plant and animal cells.

Performance Objectives

This lesson fits the grade seven topic, “Cells and Heredity.”

1. Students will be able to describe the anatomy and physiology of plant and animal cells and their major organelles including the cell wall, cell membrane nucleus, chloroplasts, mitochondria, and vacuoles (meets South Carolina standard 7-2.1) 2. Students will be able to compare the major components of plant and animal cells (meets South Carolina standard 7-2.2) 3. Students will practice using a microscope properly (meets South Carolina standard 7-1.1)

Materials

To complete this activity, the students will need to use compound microscopes to view plant and animal cells. Microscope slides and cover slips, wooden toothpicks, methylene blue, pipe cleaners, tape, foam shapes, and scissors will also be necessary to complete this activity.

Description of Activity

Students will first complete the pre-activity worksheet, and then they will make microscope slides of plant cells and human cells. To make the animal cell slide, the students will scrape the inside of their cheeks with wooden toothpicks and will add a drop of methylene blue to stain the cells to make them easier to see. The students will place a cover slip over the cheek cells. To make the plant cell, the students will be given a thin slice of an aquarium plant leaf or stem, and they will make a microscope slide of the leaf to observe the plant cells (To save time, the plant cells can be premade by the instructor prior to the lesson). The students will then observe each slide under the microscope followed by a discussion noting the similarities and differences between each type of cell, and the instructor will provide the names of the different organelles. Based on the students’ observations of the organelle structures, the students will discuss the function they think each organelle serves, and the instructor can adjust the students’ conclusions as necessary. The students will then use pipe cleaners and foam shapes to model the organelles based upon their observations under the microscope and the class discussion. The students can tape their models onto a piece of paper (tag board works well). The instructor can help the students to label their models by drawing a plant cell and an animal cell on the board and labeling the organelles. The students can draw arrows to their foam shapes and pipe cleaner shapes for a visual representation of the terms for the organelle. Students will then complete the post- activity worksheet. Pre-Activity

1. How are these organisims similar? Think in terms of the cells that make up each.

2. How are these organisms different? Think in terms of the cells that make up each.

3. If possible describe how are plant cells and animal cells different using the terms cell wall, vacuole, cell membrane, mitochondria, and chloroplast. Post-Activity

1. Which of the above pictures is from an animal cell? How do you know?

2. Which of the above pictures is from a plant cell? How do you know?

3. Using the T-chart below, put the following terms in the correct column (some terms may be used in both columns): nucleus, cell wall, cell membrane, vacuole, chloroplast, mitochondria

Plant Cell Animal Cell