Calculation 3: 1 and 9: 3: 3: 1

In this video-tutorial I'm going to explain how to calculate the 3: 1 monohybrid and 9: 3: 3: 1 dihybrid crosses. These proportions are discovered in the Mendelian era and are very useful for solving genetic exercises.

In order to the first ratio 3: 1 we will use the example of eye color. This proportion is found when a pure individual in one character meets another individual with another dominant individual. The resultant will not be a pure individual.

In the case of the ratio 9: 3: 3: 1 speaks of two characters is a dihybridism. In this case we will use the character of the length of the eyelashes. The question that is resolved in the exercise is what happens if two individuals intersect and this leads us to Mendel's third law that says that different traits are inherited independently of each other.

And so far the explanation! Now I encourage you to practice what you have learned with printable exercises and their solutions. You can also ask me questions about doubts you have and I will be happy to help you.