Try breeding some dragons to see if you can figure out any rules that govern which dragons have a fancy tail. Click the "Breed Offspring" buttons as many times as you like. |
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Now see if you can figure out any rules that govern which dragons have wings. Click the button as many times as you like to breed possible children from these pairs. |
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Do you have an idea about how wings are inherited? Try the two scenarios below to see if they confirm your suspicions. |
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We've reset things now - are you ready for your challenge? Zoom in on
our Daddy dragon.
Your goal will be to create a child dragon with
wings, but no legs. To inherit these traits, the child will need to have
the gene combinations
ww
and
ll
.
Now reset the meiosis and zoom in on our expectant mother dragon. Run
meiosis a few times. (Note that you will have to return to the un-zoomed
view and hit "reset" to get a fresh run).
If you looked closely, you noticed that we have a problem. The mother can only give chromosomes with the genes Wl or wL. And neither of these will help us in our quest. Fortunately, there's a catch… Zoom in on the mother and press the triangular "play" button again. The process will stop halfway through and wait for you. When it does, click on one chromosome with the tip of your mouse. See the flashing arrows? The arrows show places on other chromosomes you can click. Try it.
Congratulations, you just performed a crossover! (This is also called genetic recombination , by the way.) Zoom out to reset things, and try a few more times. Can you create our desired ww and ll dragon now? Give it a shot.
When you think you've succeeded (and before you proceed to breed the child!), zoom in on the chromosomes you crossed over and take a snapshot for your lab notebook. Write a note to go along with the snapshot describing what you did and why you think it will make the correct child dragon.
Use the cross tool to breed a new generation of dragons. Then breed two of the dragons from this new (F1) generation together. Repeat this as far as you wish. What do you notice about the dragons as you continue to breed more generations this way?
Use the chromosome tool to examine the genes of the dragons more closely. Can you find any genes that are different among the members of your F8 generation? How many generations do you have to breed until all the dragons are exactly the same?
You are creating an inbred strain of dragons in the last generations of this process. When you think you have succeeded in creating a strain, use the button above to take a snapshot of your strain for your lab notebook. Along with the snapshot, write a note describing your strain, and explain what is special about all individuals in an inbred strain of organisms. Then proceed to the next section.
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