Microscopes and Microscopic Research

Microscopes have been used to make amazing discoveries about cells and the information inside of them.



A8.2 Two Scientists using an electron microscope
We have made lots of discoveries by studying the information inside of a cell. Genes are a common molecule scientists study, and genes have provided us with so much information. Remember that genes direct the activities of our cells and that each strand of DNA is made up of many genes.


A8.3 Scientist modifying DNA
By studying these genes, we can find a cause for many different diseases. For example, a blood disease called sickle cell anemia comes from a change in a gene. Many kinds of cancer are also thought to be triggered by a gene.

In order to study these changes that cause diseases, scientists first had to map out all the genes we have. This way, they know what is normal and what is different so they can determine a cause for a disease. Scientists completed the Human Genome Project in 2003. This means they now know where every gene a human has is located.

The completed Human Genome Project now allows us to focus on the function of each gene rather than where they are located. As we figure out what each gene does and how it interacts with other genes, we can develop cures or treatments for many genetic diseases, such as sickle cell anemia or cancer.

© U.S. Department of Energy Human Genome Project, via Wikimedia Commons
A8.4 Human Genome Project logo

  Did You Know?


A8.5 DNA strand

The human genome contains 20 500 genes. About 99% of human DNA is actually junk DNA. This DNA is DNA that does not code for a functioning gene. Scientists are researching why we have so much junk DNA and what its purpose might be.
A8.6 Stem cell possibilities
The medical field has also been doing research around the use of stem cells. Stem cells are cells that have the ability to develop into any kind of specialized cell. This is really important to medical treatments, as there are a number of specialized cells in the human body that once damaged cannot be repaired. An example of this would be spinal cord injuries. If a nerve cell is damaged, it cannot be repaired. If the injury is bad enough, it could leave the person paralyzed. Doctors have been doing an experimental treatment where they insert stem cells at the site of the injury, and the stem cells take on the kind of cell in that area. This replaces the damaged cells and treats the injury.

Stem cells are also being researched as a treatment for organ failure and organ transplants. Rather than having to wait for an organ to be donated, doctors could potentially grow a new organ to replace the old organ with. This would save thousands of lives.

There is a large amount of debate around stem cells, as up until recently, the majority of the stem cells used came from human embryos. The embryos used were often created for fertility treatments. When they were not needed anymore, they were donated for research.

We have now discovered a way to genetically modify adult cells to turn them back into stem cells. Scientists are still testing these new stem cells out (called induced pluripotent stem cells, or iPSCs) to see if there are any significant differences between them and embryonic stem cells. If there is not, we could use these iPSCs for research and medical treatments rather than embryonic stem cells.

A8.7 Organ transplant

  Digging Deeper

A8.8 iPSC creation and uses

iPSCs are a very recent discovery, and scientists are still researching them. Go to the following link for more information on this research on stem cells and iPSCs. https://stemcells.nih.gov/info/basics/6.htm

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©Laozhengzz, via Wikimedia Commons
A8.9 Cell communication
Scientists have been researching how cells communicate with each other. Using microscopes such as scanning electron microscopes that allow for observation of live cells, scientists have been able to observe cells and determine how they talk to each other. Cells release molecules called messenger molecules that travel through the blood stream and attach to receptors on the membranes of other cells. These receptors then start a chain reaction that carries the message to the correct location inside of the cell. This is very similar to a lock and key. The messenger molecule will only fit into specific receptors that start the correct chain reaction.

  Read This

Please read pages 261 to 264 in your Science 10 textbook. Make sure you take notes on your readings to study from later. You should focus on how microscopes have helped make important discoveries. Remember, if you have any questions or you do not understand something, ask your teacher!

  Practice Questions

Complete the following practice questions to check your understanding of the concept you just learned. Make sure you write complete answers to the practice questions in your notes. After you have checked your answers, make corrections to your responses (where necessary) to study from.

  1. Why is cell communication valuable to society?
Scientists use their knowledge on how cells communicate to bind substances to the cells or the membranes of the structures that they want to look at. This helps scientists to diagnose certain diseases caused by viruses, bacteria, and protozoans. This technology is also helpful in understanding how cells interact. This knowledge will help scientists with future research and treatment of HIV and cancer. You will learn more about these treatments on the next page. 
  1. How do stem cells differ from other kinds of cells?
Stem cells can mature into any kind of specialized cells. A normal cell can only divide into copies of itself; it cannot change its specialization.