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Natural Science - Year II

Unit 45: Inheritance Lab

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Lab Assignment for Unit 45

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Unit 45 Laboratory Activity: Breeding Pea Plants

Goal: Repeat Gregor Mendel's Pea experiment.

We can simulate the pea experiment with the online Pea Soup lab, put together by Bill Kendrick.

Click on "Start the experiment".

The pea plants are either yellow or green. Yellow is a recessive color and occurs only if both parents contribute a "y" characteristic for color. Green is dominant, so if the characteristics inherited by the plant are Yy or YY, the plant will be green.

Pea plants can also be smooth (W, dominant) or wrinkled (w, recessive). If the child has a Ww or WW pair, it will be smooth. If it has a ww pair, it will be wrinkled.

Answer the following questions:

  1. What happens if you breed a pure plant (for example, YYWW or yyww ) with itself?
  2. What happens if you breed a yyWW and a YYww plant?
  3. How can you breed a pure plant (all children have the same characteristics)? See if you can do so from the starting point and explain your choice of breeding parents for each generation. How many generations did it take you?

If you are really into computers, you might like to look at the source code in C for the experiment, which uses a random number generator to set the original distribution of characteristics.