Online College Courses for Credit

Unit 1: Introduction to Punnett Squares

Unit 1: Introduction to Punnett Squares

Author: Amanda Soderlind
See More
Fast, Free College Credit

Developing Effective Teams

Let's Ride
*No strings attached. This college course is 100% free and is worth 1 semester credit.

47 Sophia partners guarantee credit transfer.

299 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 33 of Sophia’s online courses. Many different colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.


Objectives and Instructions

Lesson Objective:

Given a word problem regarding inheritance of a widow’s peak trait, the learner will be able to identify the genotype of both parents then properly develop a Punnett square with parental alleles.



Please watch the video tutorial to learn about the basics of Punnett squares. Using that information complete the practice problems below the video and score yourself using the key provided to check your understanding of the concepts. When you feel confident in your understanding of the concepts, complete the 5 quiz questions in the upper right corner of this page.


Have you ever wondered why some members of a family look similar? Or why exactly your eyes are blue or your hair is brown? The reason for this is related to your genes. Genes are bits of genetic information passed down from parents to offspring. In genetics we can use a basic tool called a Punnett square to predict the outcome of offspring when we know the genes of the parents. Below is an example of what a Punnett square looks like. In order to set up a Punnett square you must know the genotypes (letters used to represent alleles) of the parents. The video tutorial for this unit will give you more details on basic concepts of heredity and how to set up a Punnett square. 




Video Instruction

Practice Problems