A Genetic Cross Using a Dpy and a Lon Mutation

Overview: This experiment is designed for students to observe inheritance of mutations over three generations.

Goals: Over the next few weeks, you will discover:

  • What are genes?
  • What does it mean for a gene to be mutant?
  • How are mutations in genes inherited?

Starting Facts:

  • Since round worms have a 1 week generation time in our 15°C incubator, there will be a new generation each week.
  • Wild type male worms can mate with mutant hermaphrodite worms.
  • A mutation in the dpy-7 gene causes worms to be dumpy or short.
  • A mutation in the lon-2 gene causes worms to be longer than normal.

The Experiment:

On _____ agar plates with bacteria food we placed _____ dpy-7 hermaphrodites and _____ wild type males.On _____ agar plates with bacteria food we placed _____ unc-55 hermaphrodites and _____ wild type males.

What happens next?

  • These round worms will mate today.
  • Their offspring will be born tomorrow. Each worm can have 300 "babies".
  • The offspring will grow to adulthood for us to observe next week.

Your Predictions:

  • When a wild type male mates with a Dpy hermaphrodite, what will their offspring look like? 
    •
  • When a wild type male mates with a Lon hermaphrodite, what will their offspring look like? 
    •

    Diagram the crosses: