Lesson 5 — Probability


Get Focused

Working with genetics has much to do with predicting outcomes. Similar to tossing a coin to decide who kicks the ball at a football game, a certain amount of chance is always present in genetic outcomes. The players at the game know that there are only two possible outcomes, and the likelihood of either is 50%.

By reviewing how probabilities of traits work together and by learning the product or addition rule, you will be able to predict more reliably how a trait or traits should move from generation to generation.

In this lesson, you will learn how to predict the genetic outcome of future generations by examining numbers and ratios. Patterns can give the likelihood of a trait remaining hidden or being expressed.

In this lesson, consider this focusing question:

  • How can ratios be used to analyze types of inheritance or to predict the possibility of a trait appearing in the next generation?


Biology 30 © 2008  Alberta Education & its Collaborative Partners ~ Updated by ADLC 2019