02. In the nucleus
Outcomes:
> Generate an explanation of how large amounts of genetic information is stored in the nucleus
Packaging the Genetic Code into the Nucleus: A Collaborative diagram
How is so much genetic information stored inside cells?
Which structures enable genetic information to be stored?
Each of us has enough DNA to reach from here to the sun and back, more than 300 times. How is all of that DNA packaged so tightly into chromosomes and squeezed into a tiny nucleus?
"The haploid human genome contains approximately 3 billion base pairs of DNA packaged into 23 chromosomes. Of course, most cells in the body (except for female ova and male sperm) are diploid, with 23 pairs of chromosomes. That makes a total of 6 billion base pairs of DNA per cell. Because each base pair is around 0.34 nanometers long (a nanometer is one-billionth of a meter), each diploid cell therefore contains about 2 meters of DNA [(0.34 × 10-9) × (6 × 109)]. Moreover, it is estimated that the human body contains about 50 trillion cells—which works out to 100 trillion meters of DNA per human. Now, consider the fact that the Sun is 150 billion meters from Earth. This means that each of us has enough DNA to go from here to the Sun and back more than 300 times, or around Earth's equator 2.5 million times! How is this possible?"
Annunziato, A. (2008) DNA Packaging: Nucleosomes and Chromatin. Nature Education 1(1):26
Activity:
Look at the attached picture that shows the way in which genetic information is stored inside eukaryotic cells.
Working in pairs you be will producing part of a whole diagram that shows the relationship between the various structures that enable the effective storage of genetic information inside each and every one of our cells.
Each pair of students will be allocated a structure which they will research and represent on A3 paper. Each pair needs to successfully produce their poster so that it can be coherently joined with the other posters to show how all of the structures are related to each other. So, 6 posters will joined together to make a larger poster which we will display.
Make sure you plan your contribution before you put it on the A3 paper.
These structures are:
1) Nucleus
2) Chromosomes
3) Nucleosomes/Histones
4) DNA double helix
5) Genes
6) Base pairs
In order to do this successfully you will need to ensure that any new scientific words are clearly defined so that your pair and the rest of the class clearly understands them from your part of the poster.
Here are some resources to help you
