Importance of Microscopes

The cell theory is an important theory as it has formed the basis of the study of biology.

A2.11 19th Century Microscope
Without the cell theory, scientists would have no idea how the basic functions of life are performed or what living organisms are made of. It is amazing to think we are all made up of billions of cells.

The cell theory could not have been created without the help of microscopes. The microscopes used by these scientists were not nearly as strong and sophisticated as the ones we have today, but they allowed the scientists to observe cells. In the next lesson, we will take a look at the development of microscopes and the amazing technology we use to look at cells today.

  Digging Deeper


A2.12 Newborn baby with microcephaly caused by Zika
You may have heard about the Zika virus, which is spread by mosquitos, on the news in previous years. There was an outbreak of this virus in the Americas in 2015–2016, which caused pregnant women and women of child bearing age to avoid vacationing in warm places. The virus causes babies with underdeveloped brains to be born. Many of these babies do not survive. It was declared a global health emergency, and scientists are currently working on a vaccine. Go to the following links for more information on the Zika virus.

The Biology of Zika Virus

Zika Outbreak: What You Need To Know

  Problem Solving Activity


How did Schleiden and Schwann follow the process of scientific investigation?



The process of scientific investigation is followed by scientists all over the world. Usually it is followed without intention; instead, it naturally occurs as we investigate a question.

The process of scientific investigation:

  1. Identify the theory or ideas behind the experiment. What do you need to know before starting?
  2. Create a focused question you want to test. If your question is too broad you will not be able to create an experiment to test it properly.
  3. Create the experiment.
  4. Decide how to collect and record the data or evidence from the experiment. For example, is a table going to work or should you take a picture?
  5. Review the evidence and data and determine what it means. Did it answer your question? If so, what is the answer? If not, what can you change to get an answer? 

Reread the information about Schleiden and Schwann. Think about the process outlined above and try to pick out the places where these two followed it. Please click on the analysis tab to complete the analysis questions. You will need these answers for your Assignment A1.
Describe how Schleiden and Schwann followed each of the five points of the process of scientific investigation. You will need some of your answers for Assignment A1: Lesson 2.

Use this answer to help you with question 5 in Assignment A1.

  1. Schleiden and Schwann wanted to see if all living things were made of cells. If this was true, they wanted to see what their function was.
  2. The experiment they created was to observe many different living things to see if they all contained cells.
  3. They collected evidence by observing the different cells and making drawings or writing descriptions of what each looked like under their microscopes
  4. When they reviewed the evidence, they found all living things were indeed made up of cells. They also discovered all life functions were performed within these cells.