4th Grade Microscopic World Unit Blueprint—Helpful Teacher Tips
Helpful Teacher Tips
Pre-Unit Information
For the overall development of skills and concepts, follow the sequence of lessons exactly as listed on the unit blueprint.
The unit combines lessons from STC Microworlds and teacher-created lessons. Since Microworlds uses the word "lesson," "learning experience" will be the term used to describe each lesson within the blueprint. If the learning experience is from Microworlds , the page number in the teacher's guide will be referenced. Otherwise, the directions to the lesson will be described within this "tips" document.
Continue to use the same student jobs utilized in previous units this year, such as materials manager, throughout this unit.
Advanced Planning
- Advanced planning is critical due to ordering living organisms. The science clerk will order the specimens according to the unit calendar.
- First you will need to plan for the arrival of the single-celled organisms used in Learning Experience 7. Next you will need to plan for Elodea, which is in Learning Experience 10. Also remember to request an onion. Please give the science clerk several days advance notice.
Substitutes
- Please refrain from having a substitute facilitate a lesson with live specimens.
LE 1: Observing a Penny
This Learning Experience is in the STC Microworlds Teacher's Guide (pages 9-12). Be sure to read the entire lesson. This activity is a foundational one for the unit, focusing on observational skills and the proper use of magnifiers. Use the activity sheet on page 13.
Students may enjoy challenging their family members to discover the hidden picture on a penny.
LE 2: Dot to Dollars
This is a teacher-created lesson.
Advance preparation: Each group of students, working in teams of 3-4, will need the following materials, cut into small pieces:
Dollar bill, business card, photo, letter "e"
Start the lesson by discussing various properties of matter such as texture, luster, shape, size, etc. to help guide students in making more detailed observations. Remind students about making quality observations and sketches, especially from the Matter unit.
The students will first observe the object with the naked eye then follow with the magnifier. Students will use the teacher-generated observation sheet to both illustrate and write their observations of each of the four items.
The lesson provides a great opportunity for observing students' team skills and collaborative techniques.
Be sure to collect and save these materials for subsequent years.
LE 3: Communicating your Observations
This lesson is in the STC Microworlds Teachers Guide (pages 15-19) but should be taught with MANY modifications. Be sure to read both the background and materials sections on pages 15 and 16.
Materials to be used include yarn, burlap, and screen wire. We are NOT using pencil shavings.
Procedure: Working in teams of 3-4, the students will observe the three objects listed above, using the magnifier. Allow sufficient time to observe the objects. The students should record their observations through writing and sketches. Use the teacher-generated sheet for this part.
LE 4: Using a Microscrope
Video: How to Use Simple Microscopes (use this interactively by pausing it from time to time for discussion)
Teacher models the proper use and care of a microscope, accurately naming the basic parts. Review and reinforcement of the parts' names is only for students to share common vocabulary. DO NOT require that the students memorize the names; nor should they be quizzed on these parts. Use the microscope-labeling sheet. Please remember to have students place the microscopes on a table, desk, or counter rather than the floor. Also, the students should not be tilting the microscope.
Allow time for each student to practice handling and using the microscope by providing one commercial slide. The purpose is for students to become familiar with microscopes. In later lessons they will delve into a variety of slides for observational purposes.
LE 5: Strands of Thread
This is a teacher-created lesson. It provides the opportunity to discuss field of view and depth of view. Slides with three pieces of intersecting thread are used in this lesson. The slides have been added to the microscope cart. Students are to view the slide and make drawings and observations on the teacher-created sheet. The lesson allows students to realize that when an item is multiple layers thick, one can't see through it. They will realize that the light from the mirror is partially blocked. Since thread is a common item, the students also have an opportunity to focus on the details they see and how to draw them. Emphasis should be placed on detail, scale, color, and accuracy. Finally, the depth of view idea is revisited in Lesson 7 (live specimens), Lesson 10 (elodea slides), and Lesson 11 (slides of different cells from the same organism). It is appropriate to distribute and discuss the Drawings and Observations Checklist . Throughout the unit, students should be using the checklist as a guide for self-assessing their work and growth. During class discussions of drawing and observations, the checklist should be referenced.
LE 6: Introducing Microscopic Life in a Pond
The intent of this lesson is to introduce the students to the world of single-celled organisms that they cannot see with the naked eye. This provides a connection between the macroscopic and microscopic worlds of living things. It links this unit to the Living Environment unit.
Supplemental Resources:
- Read What's Smaller than a Pygmy Shrew? by Robert Wells to the class. It is suggested that you stop after reading the page with the large paramecium picture (approximately two-thirds of the way through the book). The remaining part of the book is about molecules, atoms... If the students are interested, they can always finish the book on their own. As you are reading, focus on the size of organisms. Once you get to the cells part, emphasize that there are tiny living things, which can't be seen by the naked eye, that are made of just one cell.
- Read and discuss a second book to the class to further anchor the idea of single-celled organisms and their place in the ecosystem/food chain. Any of the followings books or parts of books would be sufficient:
- Food Chains in a Pond Habitat (Only the last page addresses single-celled organisms; however, it emphasizes the food chain and microscopic size of some organisms that live in a pond.)
- Through the Microscope by Ron Taylor (Read pages 14-17. The section emphasizes the different kinds of microscopic life in a pond and how they move and eat. The information in the book gives students background information on the specimens they will observe in the next lesson. Note: You do not need to read the section on reproduction.)
- Mysterious Microbes by Steve Parker (Read pages 14-15. The section emphasizes the different kinds of microscopic life in a pond and how they move and eat. The information in the book gives students background information on the specimens they will observe in the next lesson.)
- Single-Celled Organisms
LE 7: Investigating Single-Celled Organisms
Live, single-celled organisms to investigate: euglena, paramecium, amoeba, blepharisma, stentor, and vorticella. Approximately two prepared slides of each specimen have also been added to your kit. Students who have difficulty finding the specimens can use the prepared slides. It is also helpful to put the prepared slides on a microscope and allow students to view them as a means for checking what they should see with the live specimens.
Quick Points:
- Life span of organisms is very short, so plan to use them as soon as you receive them.
- Keep lids off and aerate. Do not place the containers in direct sunlight.
- Have students use low and medium power, not high.
- Use teacher-created data sheets to record observations, both written and sketched.
Supplemental Resource: View the video Smaller Than the Eye Can See.
LE 8: Exporing Single-Celled Organisms through the Internet
Because it is almost impossible to view these microorganisms in action, the students will explore them by going to different web sites that do provide a wealth of visual experiences. The web sites further advance the idea that even single-celled organisms need food, water, and an environment in which they can live.
Suggestion for facilitating understanding of the needs of single-celled organisms and synthesizing information from web sites: Create a Venn diagram comparing and contrasting an amoeba (or some other single-celled organism) and an isopod. Students should find many similarities, such as they move, eat, and need water and a place to live.
Sites to view:
Teacher background information on Paramecium and Stentor
Drawings and information on numerous single-celled organisms (select protozoa)
http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/index.html
Moving Amoeba Video
http://www.bms.ed.ac.uk/research/others/smaciver/A.prot.Loc.mov
Information and pictures of Euglena living in a pond
http://www.btinternet.com/~stephen.durr/euglena.html
For more websites, click here
LE 9: Microscope Performance Assessment
Use the teacher-created checklist to determine students' proper handling and proficiency with the microscope.
LE 10: Multi-Cellular Plans
Elodea
- Advance preparation required. Teacher will prepare these slides. Peel a super thin layer off the leaf, place it on the slide, adding a drop of water. Then place the cover slip on top. Students should be able to prepare their own slides.
- Use low power and medium power. Use teacher-created data sheet.
Onion
- Read STC Microworlds Teachers Guide p. 67 for background info. See illustrations on pages 68-69.
- Follow same procedures used for the Elodea. Use teacher-created data sheet. Students should be able to prepare their own slides.
LE 11: Specialized Cells within an Organism
Purpose: Compare and contrast different cells within an organism. (Example-flower=leaf, petal, stem...). This is only an introduction to this concept. We simply want students to realize that not all the cells in a multi-cellular organism are exactly the same.
Use teacher-created data sheet and the plastic Micro-Data slides (also called E-Z View slides), which will be added to the microscope cart.
If time permits and student interest exists, allow them to view more commercially prepared slides.
LE 12: Summative Assessment
Use teacher-created assessment sheet.