Station 9

Station 9: Differences in DNA

Directions: Read the information below and use it to answer the questions in your handout. 

It turns out that we share at least 65% of our DNA with virtually all complex life forms on this planet.

While this naturally begs the question, “with our DNA being so similar, why do different species look and act so differently?” I’ll give you a simple analogy to help you reason this out for yourself:

Imagine you are a baker, trying to make a typical loaf of bread. Most recipes involve a basic mixture of flour, salt, water, and yeast. With just these ingredients there are over a hundred types of bread in the world. This is accomplished by varying the shape of the loaf, time in the oven, amount of steam used, proofing time, etc.

DNA uses many of the same tricks to make bodies of different shapes, sizes, and mechanics. The order of the nitrogenous bases and regulation of particular gene expression is what gives rise to a tremendous variety of phenotypes.