Microscopes

Objective:

Understand the impact microscopes had on science investigation.

Purpose:

1. Research Leeuwenhoek's life and invention and explain why the invention was important
2. Explain how microscopes have changed
3. Explain innovations and technological changes in viewing microscopic organisms
4. Explain why we need information about microscopic organisms
5. Complete research on Leeuwenhoek, microscopes

Preparation

Review class notes; research Leeuwenhoek; research information on microscope use

Evaluation:

Rubrics: Content, Effort, Neatness, Following instructions, Creativity
One of the more effective assessment strategies for microscope activities is constructing portfolios to represent student work. A portfolio is a systematic gathering of student work to represent learning and accomplishment. Some things that might be included as portfolio entries are: drawings and narratives about what is seen through the microscope, group projects showing microscopic features of living things, work that demonstrates the identification of features in and an understanding of the function of living things, student-generated research related to an aspect of the microscopic world, and work that demonstrates the use of the microscope in problem solving.

Robert Hooke

Have available the following materials:

1. single-edged razor blade

2. jar of water

3. eyedropper

4. dissecting needle

5. microscope

6. microscope slide

7. cover slip

8. cork

Cell Model

Topic: Cells October, 1996

Credits: Patricia (Pat) Brickley, Battle Mtn. Jr. High, Battle Mountain, NV.

Objective: Students will be able to:

Compare and contrast the structures of plants and animals.

Demonstrate and understand the 3-dimensional aspect of cell structure.

Identify the various parts of plant and animal cells.

Purpose:

The purpose of this activity is to provide students with a hands-on activity which will enhance their understanding of the 3-D characteristics of cells while reinforcing their knowledge of plant and animal cells.

Materials:

Play-doe, food coloring or tempera paints (red, purple, green, blue), 1 pair disposablegloves, yarn or undercooked spaghetti, pepper, plastic-bubble packing, aluminum foil, plastic wrap, pencil shavings, scissors, 1 large knife, glue

• Cytoplasm -- play-doe (plain - approx. 260g or 8oz)*

• Endoplasmic reticulum -- yarn or cooked spaghetti

• Ribosomes -- pepper

• Mitochondria -- play-doe (purple - approx. 7g)**

• Vacuole -- plastic-bubble packing

• Lysosome -- play-doe (red - approx. 5g)

• Chloroplasts -- play-doe (green - approx. 10g)

• Cell wall -- aluminum foil (approx. 12" X 7")

• Cell membrane -- plastic wrap (approx. 12" X 16")

• Nucleus -- play-doe (blue - approx. 20g)

• Nuclear membrane -- plastic wrap (approx. 3"X6")

• Chromosomes -- pencil shavings

Jelly Bean

Topic: Cells October, 1996

Purpose: The purpose of this activity is to get students to think about some of the problems that arise when a cell ingests food. If possible, allow the students to observe Paramecium feeding on Congo red-stained yeast. Remind them that a cell is a fluid-filled sack, somewhat like a water balloon. Before starting the exploration activity, have the students consider the following (kinds of) questions

Materials: 1 plastic shopping bag , 1 pair of scissors ,15 cm of string ,4 pieces of wrapped candy Time:
Preparation Time: 20 minutes
Class Time: 30-45 minutes

As with Paramecium, the food particles are held in clusters within the cell; enclosed within a pinched-off portion of the Ôbag-cell's' membrane. The candies do not penetrate the membrane, but are contained within a portion of it

Evaluation:
Have students do a drawing (like the solution above) to describe the process of endocytosis.

Experiment: Plant Cells -- What Are the Parts of the Onion Skin Cell?

Objective:
To observe onion skin cells and to locate the various parts of plant cells

Materials:
Compound microscope
Slide
Cover glass
Methylene blue or iodine solution Dropper bottle

Cell DataBase

Subject: Life Science
Topic:Cells
October, 1996

Credit: Adapted from a lab by Shelly Peretz, Thornridge High School, Dolton, IL, AESPeretz@aol.com

Objective: Observe, compare and describe cell organelles in terms of their function, structure and operation.

Enter and edit information in a database. Build and sort a student-designed database.

Find records in a database.

Purpose: Students use their research to plan and create an organized data base which can be used in subsequent lessons.

Time: Depending on the resources available to students, approximately 3-4 weeks.

Materials: Reference material, computer, data base software

Preparation:

Prior to building the database, students examine a variety of materials with a microscope to gain an understanding of the cellular structure of living things.

Students should know how to determine the size, in micrometers (microm), of plant and animal cells using a small, transparent millimeter ruler. Introduce the whole class to the data base template; discuss how it is designed.

Ask students what kinds of information they use in their everyday life. Explained that a database is a software tool that helps you work with information. Within each record, there are fields or categories of information. As the records grow in number, information is easily retrieved by using the Find command. Information can also be sorted by selected fields.

A database provides students with a tool to manage information in their own way. Students are asked to make a list of all the field headings they think would be necessary to organize their cell research information. Suggested fields should include the name of the organelle (the discovery), the scientist credited with the discovery, the country, the year of discovery, description, size, number, function, what kinds of cells the organelle is found in, reference materials, and the name of the student who did the research.

Demonstrated how to redesign the database using the fields and types of information from the previous discussion. Divided into groups of 3-4 to do research about cell organelles. Group members are expected to provide help and encouragement to each other in order to ensure that all members do the assigned work. Everyone in the group receives the same grade for this project.

After students have gathered data about each cell organelle they entered it into their own database. .Students write questions that could be answered by browsing, searching or sorting their database in a variety of ways. .

Examples: What country is the most active in cell research? What reference source provided the most information about cells? Does the size of the organelle have anything to do with when it was discovered? What organelles are involved in protein synthesis? cell reproduction? What organelles are found in animal cells, but not plant cells?

• Introduction to DNA Simulation

• Subject: Life Science

• Topic: Cells

• October, 1996

• Credits: Adapted from a lab in Carolina Biological DNA Model Kit

• Objective:
  Understand the process of DNA replication.

• Purpose:
  Build a DNA molecule using the beads from DNA Lab 1. Students will then split the molecule and "cause" it to replicate.

• Time:

• Materials:
  Beads from DNA Lab 1, lab instructions

• Preparation:
  Adequate number of beads and connectors for each lab group.

Double Helix

• Subject: Life Science

• Topic: Cells

• October, 1996

• Credits: Adapted from a lab in the Carolina Biological DNA Model Kit

• Objective:

  • Understand the parts of a DNA strand;

  • Name the molecules that make up a gene;

  • Explain which chemicals are found in each part of the nucleotide.

• Time:

• One 50 minute class period.

• Materials:

  • Lab directions

  • white, red, orange, green, blue, and yellow beads

  • clear connectors
    

• Preparation:

  • Review the concept "model".

  • Students should be familiar with and have been introduced to the DNA structure.

  • They should know the vocabulary adenine, guanine, cytosine, thymine, sugar group and phosphate group.

Meiosis Chart and Model

Purpose:To arrange chromosomes on a chart that compares mitosis and meiosis.Materials: scissors, tape or glue

Cell Mural

Subject: Life Science Topic:Cells October, 1996 Credit: Linda Culp Thorndale High School Thorndale, TX 75677

Time:The class time required depends on the abilities of the students to work outside of class. 1-4 days of class time should be sufficient for an average class of students to complete this activity in its entirety in the classroom.

Materials: Markers, crayons, or other paint medium. Poster board, blank newsprint, butcher paper, or any available paper. News print can sometimes be obtained from newspaper offices at a very nominal price.

Preparation:

No preparation is needed by the teacher or the student if the teacher has previously instructed the students in concept mapping. However, it is not necessary to develop the concept map to create the mural and it is important to understand that the students are not to transfer a concept map onto a larger piece of paper. The concept map is only used to help the students organize.

HAVE YOU FOUND YOUR LONG LOST TWIN

Subject: Life Science Topic: Cells October, 1996 Credits: Lawrence Hall of Science
Objective: identify genetic characteristics in humans. use a wheel to diagram characteristics. compare wheels among individuals class.identify easily observed physical features that are inherited.time: 15