Lesson B4: Looking at Cells

Key Ideas     Unit Checklist 

  Video Lesson

Why are microscopes so important for studying living things? Watch this video to learn more.

 
 

  Lesson B4: Looking at Cells

Figure B.2.4.1 – Microscopes show hidden detail in ordinary objects, like this tree stem.
Figure B.2.4.2– Microscopes reveal that all living things are made from cells.
 


Reading and Materials for This Lesson

Science in Action 8
Reading: Pages 98–102

Materials:
Smartphone, inexpensive laser pointer (from the dollar store), small screwdrivers, bobby pin, hair elastic.

Amazing Microscopic Images

Microscopes allow biologists to observe living things that can’t be seen with the unaided eye. Scientists have developed camera technologies to take detailed pictures of microscopic organisms and cells. This allows microscopic images to be preserved and shared.

Many microscopic pictures are colourful and fascinating. Microscopic organisms can sometimes look like they come from another planet! You can click here to explore some amazing microscopic images that combine careful scientific observations and artistic aesthetics.

 Watch More

Great Things Can Come In Tiny Packages

Watch these videos to see the winning images from a microscopic photography competition. The first video is a recap of the 2012 winner.

 
 
 
 
2013 Winners

 
 
 
 
2014 Winners

 
 

 Watch More

Early Microscopes

When were microscopes first used? This video tells the story of Anton van Leeuwenhoek, who was the first person to observe bacteria through a microscope.

 
 

Lesson Activity


Using a Microscope

Instructions:

ο»ΏMicroscope Activity 1

  1. Go to this website: http://scienceman.com/test/ADLC_micro_basics/story.html 

  2. Work through the activity on learning how to use a microscope, in order. Make sure you watch all the videos in order and try all the activities. Record your answers to the questions in the "Hair Analysis Activity".

Questions:

Complete the 4 hair width estimate questions in the "Hair Analysis Activity".  Type or write your answers. When you have your answers, click the questions for feedback.

The female straight hair covers about one-third of the field of view. The width of view is 0.4 mm. 0.4 mm divided by 3 gives an estimated hair width of 0.133 mm.


The male curly hair covers about one-quarter of the field of view. The width of view is 0.4 mm. 0.4 mm divided by 4 gives an estimated hair width of 0.1 mm.


The cat hair covers about one-fifteenth of the field of view. The width of view is 0.4 mm. 0.4 mm divided by 15 gives an estimated hair width of 0.0266 mm.


The cat whisker covers about one-half of the field of view. The width of view is 0.4 mm. 0.4 mm divided by 2 gives an estimated hair width of 0.2 mm.


 
 
Microscope Activity 2

  1. Go to this website:  https://www.brainpop.com/games/virtuallabsusingthemicroscope/  (if you are asked for a login, use login: 0099 password: students)

  2. Work through the virtual microscope activity in order. This activity simulates the steps involved in using a real microscope.

  Try It! 

Make a Smartphone Microscope

Try this experiment to turn a smartphone into a microscope! 

Materials: 
  • Smartphone
  • Inexpensive laser pointer (from the dollar store)
  • Small screwdrivers
  • Bobby pin
  • Hair elastic
 
Laser pointers can damage eyes.
Never look directly into a laser pointer and never point a laser pointer directly into anyone else’s eyes.
Instructions:

  1. Stretch the hair elastic around the width of the smartphone. Adjust the hair elastic so it is located just below the camera lens on the phone.

  2. Using small screwdrivers if necessary, take apart the laser pointer and remove the small glass lens.

  3. Place the flat side of the laser pointer lens over the smartphone camera lens.

  4. Slide the bobby pin under the hair elastic. The hair elastic should hold the bobby pin against the smartphone.

  5. Stretch open the bobby pin around the laser pointer lens, to hold the lens in place.

  6. Turn on the camera app on the smartphone. Observe objects and take photos with your smartphone microscope. What amazing microscopic images can you create?

  7. Watch this video to see this experiment and its results:

 
 

  Connections 

Figure B.2.4.3– The microscope is an essential tool for studying living things.
Figure B.2.4.4– Paper microscopes can be created for 50 cents each. Image by Cybulski J, Clements J, Prakash M .


Figure B.2.4.5– Foldscopes can do some amazing enlarging of tiny objects. Image by Aaron Pomerantz. 
Connections – Technology
>> Paper Microscope

In developed countries, diseases are diagnosed using microscopes. Healthcare workers take swab samples from a person. They look at the samples under a microscope to determine the type of microorganism causing the disease so it can be treated properly.

Microscopes are expensive, heavy, and bulky machines that can easily break if they are not cared for properly. Many healthcare workers in developing countries do not have access to traditional microscopes because of their high cost. This means they cannot diagnose and treat diseases properly.

Inventors are working on solving the problem of accessible and affordable microscopes. They are making microscopes that are printed on a piece of paper and folded up! These β€˜foldscopes’ are easy to transport, don’t break easily, and are inexpensive to make. Paper microscopes are an invention that could improve healthcare for a billion people around the world.

 Watch More

Paper? Scissors? Microscopes Rock!

Watch this video to learn more about the paper microscope invention.

 
 
 There is no self-check for this lesson. Please move on to the next lesson!