Here is a problem you should be able to solve using what you learned in this tutorial.
Humans cannot synthesize vitamin C (ascorbate), and so we must obtain it from our diet. Many mammals, including mice, can make ascorbate. In the time since our line diverged from that of rodents, we have lost one enzyme, gulonolactone oxidase, the final enzyme in the pathway of ascorbate synthesis (if interested, read more).
This means that humans have an evolutionary ancestor that possessed a functional gulonolactone oxidase gene. It stands to reason that humans should possess a nonfunctional remnant of that gene (called a pseudogene).
Can you find a remnant of the gulonolactone oxidase gene in the human genome?
Happy hunting!